Almost everyone who has memories of 2001, knows where they were and what they were doing on September 11.

Many say it is the Pearl Harbor or JFK assassination of Generation X.

But what about those people in the air on that fateful day?

Reddit user n8th8n0101 asked "To the people on a plane on 9/11, what did your pilots tell you when they grounded all flights?"

Here are their stories.

My wife and I were flying from London to Los Angeles - about three hours into the flight my wife asked why the flight map on her video screen showed the plane flying east instead of west (apparently the 747 had just completed a slow turn). At that exact moment the pilot came over the speaker and told us the plane would be going back to the UK because there had been an incident in New York and that US airspace had been closed down. All passengers were requested to remain in their seats and the air phones were turned off. We ended up landing in Cardiff, Wales -- there were several 747s at the runway by the time we arrived.

The minute the plane landed dozens of cell phones were ringing. All the events of the day came all at once -- towers hit, towers collapsed, Pentagon hit and another plane crashed in PA and worst of all thousands had died. People were just stunned learning all these details. The airport terminal was just overwhelmed -- there were thousands of people and the support staff were doing their best to assist us but they had little information or resources. First they said that flights would be departing the next day so we could be getting overnight accommodation. My wife said there was no way that anyone would be flying anywhere in the near future and our best bet would be to catch a train back to London. Fortunately there were several passengers that had the same thought and somehow they arranged to get a bus chartered to take us back to Heathrow. While waiting for the bus we found a television and were able to see the images of the day. People were watching in stunned silence and many were weeping. Upon boarding the bus my wife and I shared a set of earbuds which was plugged into a radio that had a US feed going through local UK stations -- the news just kept getting worse and it was clear that the world had changed while we had been in the air. At about 1am the bus arrived at Heathrow which was absolutely deserted. Eventually we made it back to our flat in Weybridge -- we stayed up watching CNN International for the next few hours and as the sun came up we finally got some sleep.

It was a day we have spoken of often since that time and one we will never forget. I still have the boarding passes in my desk.

A friend of mind was a pilot for Singapore Airlines flying Singapore to Seattle. He was diverted into Canada, but only told the passengers the bare minimum that they were being diverted to another airport. It wasn't until they got inside the airport terminal and saw the TV that they understood why they were diverted. (Even he was surprised at the scale compared to what ATC told him.)

He was also the pilot in command of the first commercial aircraft to enter US airspace when it was reopened, and he recalled being terrified of deviating from his planned track. He had an uneasy feeling in the back of his mind that there was likely an F-14 a few thousand feet above him ready to vaporise them if he moved unexpectedly.

Not me but my mom, who was and still is a flight attendant. She was working a flight from DFW-BOS that morning, they were approaching the northeast when they were diverted to Akron, OH. I'm not sure what she was specifically told but I know they knew something was up. Their flight communications are even included in transcripts from that day.

By that time both towers had been hit and they were headed west over Pennsylvania to land. My mom said they were all on edge not really comprehending the severity of the situation and wondering whether they might be hijacked themselves. They were communicating with Cleveland on the ground when the hijacking of United 93 began over western PA, so there was communication between both flights and ground trying to confirm that the screaming etc they heard on the frequency was really a hijacking? Apparently United 93 was right behind them and my mom says the crew was back and forth up in the cockpit and in the galley looking out the windows trying to see the plane, while trying not to scare passengers.

She was stuck there for a few days until finally renting a car with some crew and driving back to TX. Was supposed to be a simple turn around run that day and she didn't bring any luggage. She always carries an overnight bag now just in case and was the first person in my family to get a cellphone immediately after this.

The airline gave crew optional 6 month leave in the months following. Where I grew up there were many airline families, some took leave and some didn't but my mom said she had to go back to work without interruption or else she'd never be able to get back on a plane afterwards.

Me and my brother were on our way to NYC this day. Our flight had barely left Paris (CDG) when we suddenly went into a descent. The Captain made an announcement that they had been ordered to return to Paris but couldn't comply due to the by then already crowded airport. So we landed in Dublin.

The airline told us that we were to be flown back the next day, but nobody really believed that, news to the why and how still being scarce.

We were free to leave the airport though, so me, my brother and a couple of guys from our flight shared a cab into town, going for a pub crawl. When in Ireland...

Where I met a girl whose flight got grounded too. Long story short:

Our kids are 6 & 9 and remind us every day: Nothing in this world is so bad that it doesn't have an upside to it.

I was flying Hong Kong to London, so wasn't subject to the flight groundings, but the pilot told us there had 'been an incident' in New York and there would be increased security at the terminal.

Arrived at Heathrow and there were dozens of police walking around with sub-machine guns (English police might not be regularly armed but they do not mess around when they feel they need to be.) Still not sure what's up, but definitely something serious.

My parents grabbed a newspaper to try and figure out what happened and flipped through the very scanty initial reports with the big picture of the burning towers on the cover, while queuing for security . Person behind them asked if they could have a look and you could subsequently hear people gasping one by by one as the paper made its way down the queue.

I was flying from Atlanta to Denver. Our flight was forced to land in Tulsa, OK. We were told that there was a terrorist attack in NY and that our aircraft had been ordered to land. The pilot did not mention that ALL aircraft had been ordered to land. As the only brown person on board I thought: Great, they must think that I am a suspect and now we have to land.

Once we landed and I saw all the planes jamming the tarmac, I realized that it was something really big.

My dad flew on 9/11 from Newark to Boston for work. He was on an earlier flight than any of this. Once he touched down in Boston and heard what happened, him and his coworker drove home (back to NJ) from Boston. Typically it's about a 4 hour drive. It took them almost 9. They didn't have to drive home but wanted to know we were okay. There was also barely any cell coverage on my home town end since we were so close to NYC.

I know this doesn't answer your question directly, but man this day hits home for me. It eats my dad alive to this day how he still believes he saw those guys in one of the airports and didn't know it.

I could see the smoke rising from my middle school like no tomorrow was in sight. No one went back to school for about 2 weeks. A lot of kids I went to school with had family members pass away. The anniversary always haunts me. I visited the 9/11 memorial and museum in NY a few years back with this girl I was seeing. She had never been to NY before and I felt crazy when I honestly started to cry inside (the museum). All the emotions got to me at once.

It's a day I'll never forget. And definitely a day that many more people other than myself will never forget for even worse reasons. I feel incredibly lucky to have a dad that's still alive today, when many of my friends do not have parents or relatives that are so lucky.

~ The 9/11 museum is very well done but I wish I was a little more mentally prepared before visiting it. I expected it to be more "cold statistics" and maybe lists of names but it's not that at all. For anyone who hasn't been, there are videos and pictures and stories of all the people who died that day, memories from their families, voicemail recordings of calls from the day. The last phone calls from people who were in the buildings and realized they weren't getting out. Stories from people who weren't in the office that day and in a blink of an eye lost every one of their coworkers. It's haunting and tragic.~

*We were told when we went in to expect it to take 2 hours to see everything. 7 hours later I walked out. I cried. A lot. I'm a 33 year old guy from the UK.

Nothing can prepare you for the room with the Pennsylvania crash calls. Nor the room with the jumpers from the WTC.

I was more emotionally exhausted than I have ever been after finishing.*

I was 9 when 9/11 occurred and my family were returning home from a birthday trip to Disney, (my birthday is September 12th, 1991, so I was turning 10 that very next day) so Orlando to Kansas City. I don't remember the specifics but it didn't feel like we were in the air long at all (our flight had been at 8:20) before the captain had come onto the overhead speakers to tell us that there had been some pretty serious incidents occurring in New York City and that they were told to land as soon as possible and that we'd be diverted to Houston.

As soon as we landed, my dad had called my uncle (who lives in Hackensack, but worked in NYC) and my uncle had told him everything. My dad literally exclaimed into a kind of gasp-sob and that was the first and only time I've ever come close to seeing him cry. When we got off the plane, it was all over the televisions throughout the airport. My mom and dad practically clung to us the entire time from the airport to our hotel nearby.

The whole thing is something I cannot and will not ever forget.

My step dad was a pilot flying small private jets, and was in the air when it happened. He said they just told him to land immediately and he had to go into the airport to find out why, and what happened, and go back to the plane to tell the passengers.

I used to work with someone who owned a small plane. He was grounded for months, because his plane was parked in a no-fly zone. I don't recall what he was too close to -- whether it was a major city (Seattle), major airport, or military base.

Same thing happened with my dad, he was riding a chartered business flight from the Midwest toward the east coast. Had to land somewhere in the middle. Dad & coworkers got a rental car to keep going, but the pilot had to stay with the plane for weeks.

It's so surreal to see the US airspace completely empty.

Here is a time lapse of the day.

(The pilot said) nothing...complete silence about it. I was flying from Toronto to Montreal. I noticed that the breakfast service ended abruptly and the stewards were acting funny, standing at the bulkheads and visually scanning the passengers. I listened to hear if the plane sounded funny or was behaving oddly...nothing was out of the ordinary so I went back to reading my paper.

Disembarked into a sea of people in Montreal, when I came down the escalator I didn't know where I was going to stand...that many people.

Many, many Americans that had no idea they would be visiting Canada that day. They were on the PA asking for people with extra rooms to lend, and Montreal'ers took them all into their homes...within an hour they were saying they had enough available rooms.

Not entirely plane related, but my Dad worked near the towers and got off the train to see the second plane crash. It really messed him up inside. We lived in the Bronx, and everyday he went to the Park Avenue Armory where people lined up to find out about their loved ones.

My Dad noticed that many didn't speak English and they were having a hard time communicating. He wrote Translation Services on a piece of paper and stapled it to his shirt and spoke Spanish, French, and Russian. He got the relief effort to spread the word to get translators. It was all over the radio and TV.

The Japanese government heard and sent their best translators by special permission on a direct flight to New York (one of the few planes that could come to New York.) A Japanese bank had work space in the towers, and the relatives of the workers also came.

By the end, hundreds of people came, even those of more obscure languages from Algeria and Azerbaijan, among others. There was a fleet of Punjabi, Afrikaans, Creole, Korean, Italian, Spanish, French, Portuguese, Polish, Chinese. It's wondrous to see how something as simple as talking binds all of us. The City began implementing translation services everywhere since.

I was 12 years old at the time and didn't understand the impact. Today at age 28, I know my Dad was a hero.

Link to: an article translated from Spanish to English from El Diario about my father.

Link to: the original Spanish article

My dad was an armed high ranking federal agent. He was flying from DC to Miami. He usually sleeps on flights but was woken up somewhere over Southern Virginia, and asked to come to the cockpit. The pilots told him to guard the cockpit, and that he was authorized to shoot - he spoke to someone over the cockpit communication system confirming the authorization. He was given the jump seat next to the cockpit during landing, so he could see if anyone stood up. He told me later that the reason they were allowed to continue to Miami instead of putting down in the Carolinas was because he was on the plane.

When he died in 2010, my mom showed me the piece of paper he had kept, with his notes from that radio transmission. I think my older brother has them now.

When he landed, he was met by the three guys he was flying down to meet with, and they all drove back overnight, getting back just in time to help oversee the search at the Pentagon, where he worked.

I've never seen him as shaken as the day he brought home a piece of the desk from his office.

I was on a plane from LA to Melbourne, with a stop-over via Auckland, and 9/11 happened while we were in the air.

Halfway through the flight, all the flight attendants got really nervous, and the pilot told us that due to a safety issue, the seatbelt sign was kept on throughout the flight, which we all found really confusing.

When we landed in New Zealand, there were armed guards with machine guns to greet us - which is very out of the ordinary for New Zealand. The first reports the flight attendants gave us was that it was the Empire State Building that had been attacked, that was how confused initial reports were. We were luckily allowed to fly on to Melbourne, but after that all international flights in Australia were grounded for a few days.

My parents were flying the morning of 9/11. I dropped them off at the airport and drove to work. First tower was hit as I pulled into the parking lot. Radio people thought it was just a fire at the tower. As I went into work and checked the news, it became clear a plane hit it. As I was on the phone with my buddy, the second plane hit on the live TV he was watching. That's when it was clear this was intentional.

Started to tell my boss I needed to pick up my parents, but he cut me off and said, "GO!". I called my parents as I ran to the car. The TVs at the gates had all been turned off and they announced no flights would be taking off. I raced to the airport, picked them up, and drove home to eerily empty roads and sky.

Also weird was suddenly seeing a lot of planes really low as they headed to the airport near us to get out of the air.

And what made it even more surreal was that it was such a gorgeous day. It was so clear and the blue of the sky was beautiful. It felt almost inappropriate or irreverent.

I remember when they let planes fly again, I was a little traumatized every time one would fly over. It took me months to break the habit of staring at each one, making sure it wasn't crashing.

My father worked for Delta at the time as a supervisor in the airport. He was working a flight that was about to push back when everything shut down. He had the final paperwork for the flight crew and ran down to let them know they weren't going anywhere. Air Traffic Control had just announced the shutdown to all aircraft on the ground.

No details were given over the radio, just that an incident had happened in NYC and all flights were grounded. He announced over the plane's PA that the flight was canceled due to an unknown incident and everyone could retrieve their luggage in a few minutes.

There were no TVs in the gate area back then, but a few of the shops and snack bars had TVs in the ticketing area. As people got near a TV the word spread. Everyone collected their bags and left the airport. From about 11:00 on, the airport was deserted except for airline employees.

I was on a United flight from Newark to Atlanta that morning. We were in the air when everything happened and were supposed to land about 9:00. Just before landing they held us in a"holding pattern" in the air. At about 9:30 we landed. No announcements were made on the plane.

Just as we got to the gate and people started turning their phones on, I hear phones start ringing everywhere.

"What happened...." "A plane hit what..."

At that point my phone started to ring as well. It was my wife wanting to make sure I wasn't on one of the planes. And she filled me in on what was known then. The pilot and cabin crew did not say anything about what happened in the air.

There was an eerie silence in the terminal. I did not see any TV screens. I went directly to the car rental company, got a car and started driving north, back to NY. Listening to the radio as much as I could the whole way back...

London to Chicago. Pilot told us there had been a major incident and US airspace was closed. Asked us not to talk or speculate with other passengers about the incident (to minimize panic).

We turned our phones on as we taxied on landing in Montreal. Both towers were already down and phones were going crazy, people who had managed to get a call through were sobbing and trying to explain to those whose phones wouldn't connect what they had just heard. Absolute sense of disbelief all round and it didn't really hit until I saw it on tv in the hotel.

One thing we were told at the time by the pilot was that the pilot was out of direct contact with Air Traffic Control (ATC) in both London and the USA at the time, so they were talking to the plane behind them, who was talking to the plane behind them, who was talking to ATC somewhere. So they were getting garbled second or third hand information from multiple sources about planes crashing and hijackings and trying to inform their passengers while not being sure of the information they had received themselves.

When you fly over the Atlantic there is no regular direct contact with Air Traffic Control except through high frequency radio which is only used sparingly in absolute emergencies. On 9/11 they would have wanted to keep radio traffic to a minimum in case of another hijacking.

My father was the Air Traffic Control supervisor for Logan Airport on 9/11 which is where the hijacked planes originated from. Before they hit the World Trade Center (WTC) my dad knew they had been hijacked. They lost contact and then saw on the news that a plane had hit the WTC. He called Federal Aviation Administration headquarters and they thought it was a prank. By the time the second plane hit NORAD was telling him to ground every aircraft in their airspace.

He said the hardest part was not being able to watch the news. All of his controllers desperately wanted to watch, but they had to get all of those planes down. There were several times when they thought more planes had been hijacked. He told me it was the absolute worst day of his life.

Link to: Recordings of ATC communications from that day on YouTube - at the end of the recording you hear a controller warning incoming flights to increase their cockpit security, and the controller sounds so broken and exhausted.

I was flying from London to Dallas and was diverted to Gander, Newfoundland in Canada. We estimate we must have been very close to Manhattan when the first plane hit. None of the crew would tell us what was going on, only that the USA had closed it's airspace due to an aviation incident and we would be redirected to somewhere in Canada. We landed at Gander, Newfoundland along with (eventually) 37 other jumbo jets; all 38 of those planes almost doubled the population of the town.

~This small Canadian town on an island in the North Atlantic Ocean took in nearly 6,700 people with no prior warning. Their hospitality to the unexpected house guests, from nearly 100 countries, drew worldwide accolades and inspired the Broadway musical: _Come From Away. _The airport there marks the closest point between Europe and the U.S. and is a preferred emergency landing spot for medical and other emergencies. The 38 planes came "fast and furious" into the airport. Officials spent the next 31 hours unloading luggage and people.~

After we had landed, the captain told everyone what had happened and there was of course utter shock on the plane, lots of tears (most poignantly from two middle eastern gentleman sitting across the aisle from me) and conversations. After several hours waiting on the plane eventually we were moved into the airport where we officially entered Canada as refugees(!) We were allowed our cabin bags but there was no access to the luggage in the hold.

There was hot food waiting for us in the airport and we were then moved onto school buses and driven to various places around the town, I think it was about 22:00 (10pm) by this time. Spent three nights sleeping on a church hall floor with mattresses, pillows and covers donated by locals, others slept on the fire station floor etc, wherever there was room, and were fed three meals a day by volunteers. There was just one hotel in town and the flight crews and those too infirm to sleep on the floor, were put into that. The local University opened it's computer rooms so people could email home and the local phone company put loads of phones out on the pavement to try and ease the massive queue to what we think was the only payphone in the town.

If anyone from Gander is reading this, you all have a heart of gold, the way we were all looked after.

After those three nights, we were woke up early by a British Airways member of staff about flying back to London. We were all moved onto a school bus where we sat for a long time before we were driven back to the airport. Went through the usual security procedures at the airport, reboarded the plane and took off for England.

Plane took off, everyone applauded once we were up in the air (first and last time I've ever seen that happen after take off instead of landing!) and we landed back at Heathrow. Declined British Airways' offer to book new flights to Dallas and instead accepted a refund. We decided we'd only have about two weeks of what would have been a three week holiday left and also we'd rather Americans trying to get home had the seats.

Link to: Operation Yellow Ribbon - Canada essentially became a giant aircraft car-park, 238 aircraft were diverted to 17 different Canadian airports, 33,000-40,000 people.

Link to: Tom Brokaw documentary about how specifically the town of Gander, Newfoundland came to the aid of so many stranded passengers.