Most people who were old enough at the time remember where they were on 9/11, as live TV images of the attacks in New York, Pennsylvania and Washington DC were beamed around the world.

For Americans, the 20th anniversary of the tragedy that cost 2,977 lives in their country is even more poignant, as many know people who were caught up in the terrible events that day.

Six Guardian readers share their memories of 9/11, 20 years on.

‘I could smell aviation fuel’

I was at my desk on the 36th floor of the south tower when the first plane hit. The fireball reached far enough down to fill my window. After a few moments of shock and bewilderment and having no idea what was going on, we cleared the floor and began exiting the building. I took the center fire escape and walked down. I was on about the 15th floor when security came on the PA and advised south tower residents to return to their offices as nothing was wrong in our building. I could smell aviation fuel; I decided to keep going. Shortly thereafter the first NY fireman passed us on his way up.

I reached the sub-ground shopping area and began following people to the exits as the second plane hit; people started running back in from outside and others began pushing from behind to get out. The crush of people lifted me off my feet ... I am 6ft 2in and 300lb. I finally exited the concourse by Krispy Kremes, and walked up to the railings by Saint Paul’s on Fulton Street, and turned and watched the buildings burning and people falling from the windows. I still had no idea what was going on.

Alarms were sounding everywhere. Firetrucks and police cars were zooming downtown. I realized I was in the way and turned to leave. I walked with an older co-worker, and helped her reach the Staten Island ferry terminal, I then walked to the 3 train at Fulton Street, and then changed at 14th to the F, heading home to Queens. When I got to the surface I had a clear view of the towers on the horizon, but could see nothing but a cloud of grey smoke.

At 39th Street I finally found a working pay phone (there was no cell service all day), and called my wife to let her know I was safe. I went into McDonald’s and bought a large chocolate shake and sat and waited for my father-in-law to pick me up. It was about 11am. I’ve not had a McDonald’s shake since. I was lucky. I reached home clean and (physically) uninjured. I spend the anniversary each year with my (new) family. I still have flashbacks and trouble with this time of year. Eric, 52, wholesale insurance broker, Sterling, Massachusetts

‘My daughter was on the last train under the towers, just after the first plane hit’

My daughter was a little late to work and came in on the last Path train, under the towers, just after the first plane hit. She was walking toward the elevator banks, when a man grabbed her arm and directed her outside. She couldn’t understand what all the debris was in the street. She crossed it and looked up, then called her dad and me. She told us that she was fine, that it wasn’t “her tower” that was hit. She said she would stay where she was until all her co-workers were out of the building, and then got off the line to call her fiance.

We turned on the TV and saw the second plane hit. She was a couple of blocks away when the south tower came down and was caught up in the dust cloud. She ran until she finally could get a signal on her cellphone, some two and a half hours after the first call. I am so thankful she is alive. I’m so sad for the families that didn’t hear their loved ones’ voices. I think about how lucky I am every day. I hope I always will. Sarah Phelps, Buffalo, New York

‘I will never forget waiting for ambulances that never arrived’

On that day, I was working for Jacobi hospital in its north central hospital building during the time of the attacks. Although the building was in the Bronx, its location on Gun Hill Road allowed for a view of Manhattan and the twin towers. Someone with a radio heard the first building was struck and from the windows, I could see the smoke billowing from one of the buildings prior to the second one being hit. Later that day, all hospital employees were instructed to be prepared, in the expectation that hundreds of bodies would be transported to Jacobi because it had the best burn unit in New York City. As the day wore on, no bodies were brought because there were no survivors. All employees were stunned as the wait went on into the night and the grim reality of no survivors sunk in. I will never forget waiting for ambulances that never arrived. Burroughs Lamarr, social work administrator in forensic psychiatry for the New York City department of health, New York

‘We noticed an American Airlines plane flying very, very low’

I was on the top floor of the Inter-American Development Bank in DC in a meeting with a woman whose phone kept ringing, and she didn’t answer the first few calls. Finally she did and it was her husband saying that a plane had crashed into the twin towers. She told me what he had said and dismissed it as: “He tells such stories.’’ We went on with the meeting and noticed an American Airlines plane flying very, very low. A few minutes after the plane passed, a guard came rushing into the office screaming, “Why were we still there?” He rushed us to the basement where there were many TV screens. It was there and then that we understood her husband’s repeated attempts at getting us out of her office.

It was there that we understood that the low-flying plane we saw had crashed into the Pentagon. After a few hours they let us out into the street. The size and strength of the quietness was eerie. I hitched a ride back to a friend’s house. The next morning I took a train to NYC. Once again the eerie silence when we passed the smoking area of where the towers had been just a day before was indescribable. The lines to donate blood were never ending, the positive attitude of people was very special, and the helpfulness of each and every the police I encountered evoked enormous gratitude in me. Susan Pick, 69, social psychologist, Mexico City

‘We were dispatching apparatus to the Pentagon and all over the region to staff the firehouses’

It started out as a beautiful morning with perfect autumn weather. I was at work with my day shift squad at our public safety communications center. We handled emergency calls and dispatched for the police and fire departments in Fairfax county, Virginia, a suburb of Washington DC. Our TVs were always tuned in to the news, and we watched as the first plane hit the first tower; we were of course horrified, but continued with our work. A bit later, the second plane hit the second tower and we knew that we as a country were under attack.

Then one of our call takers, who was right across from where I sat in the fire dispatch area, stood up and repeated what he was hearing from a caller on the 911 line: “there’s been an explosion at the Pentagon!” All hell broke loose after that. Our county is right next door to Arlington county, where the Pentagon is. The rest of the day was really a blur. We were dispatching apparatus to the Pentagon and all over the region to staff the firehouses.

Ultimately most every department in the DC metro area ended up at the Pentagon. Some of my co-workers in the 911 center went as well, to assist with communications on the ground. At the end of the shift, I remember walking around the center and just hugging everyone I could, and crying my eyes out. Donna Will, 61, retired public safety communicator, Chester, Virginia

‘There was a lot of weeping and a lot of hugs’

I was listening to NPR news when a bulletin came on that a plane had hit one of towers of the World Trade Center. Listened as people in the studio and on the scene tried to make sense of what had happened. Then I heard a sound I will never forget as long as I live, the sound of jet engines at full power flying very low above the reporter’s microphone, a crash, and the sound of people on the street collectively voicing their shock and horror. I knew when I heard that sound that we were under attack.

I drove to the church, realizing along the way that we would need to develop some way to allow people to express what they felt. Our secretary and I put together a very sparse service bulletin for service that would have an open mike for people to speak, to pray, to weep. Then we put the word out that we were having a service, as many churches did. There was a lot of weeping and a lot of hugs. Roger Digges, 72, retired pastor