9/11 anniversary: Victims remembered at events across US - BBC News
Former President George Bush speaks movingly about the loss felt by the nation, 20 years after 9/11.
Joseph Pfeifer, Battalion Chief of the New York City Fire Department, told the BBC about his experiences on that day. He first featured in the National Geographic documentary 9/11: One Day in America

"We were attending a routine gas emergency in the area. And at 08:46 we heard the loud noise of a plane coming overhead, and then I saw the plane aim and crash into the World Trade Center. I was the first fire service commander on the scene.

"Every first responder, when we saw the burning towers, knew this was the most dangerous fire of our lives. Everyone made their own personal decision to go in.

"I thought I might die when the North Tower collapsed. It was so confusing that we didn’t know at that point the South Tower had gone down already. But at that moment someone yelled, ‘the building is collapsing,’ and I started to run. You don’t run too far with helmets and bunker coat and pants and boots, in 11 seconds.

"We wound up ducking behind a small van, and then this beautiful summer day goes completely dark, where you can’t see anything. We hear steel crashing all around us, and glass and then things go quiet. And in the darkness, I wondered if I was still alive.

"My brother Kevin was a lieutenant in the fire service, and that day we stood just maybe a meter apart and we looked at each other. He didn’t say a word, it was just a quiet moment for a few seconds, and then I ordered him up to evacuate the building and to rescue those that were trapped.

"That was the last time I saw him."

Lower Manhattan was filled with with fireman, police, and rescue crews after the collapse of the World Trade Center Image caption: Lower Manhattan was filled with with fireman, police, and rescue crews after the collapse of the World Trade Center