Alan Treacy, the first paramedic to reach the train which blew up outside Aldgate Station, has described the horrifying ordeal that he faced, but says life must go on.

Shortly before 9am on Thursday, July 7, Waterloo ambulance station received an emergency call to an incident underground, first described as at Liverpool Street Station, and then confirmed at Aldgate.

Paramedic Alan Treacy, 42, of Weald Hall Lane, Thornwood, colleague Phil Greene and a duty manager responded.

The blast, now known to be the work of a suicide bomber, occurred at 8.51am.

Mr Treacy, a London paramedic for 18 years, and his team were on the scene by 9am. Seven people died in the attack, but everyone who was alive when Mr Treacy arrived is still alive today.

While Mr Greene waited in the ambulance Mr Treacy and his duty manager descended.

He said: "As we went down I saw the walking wounded coming up. They were covered in soot, limping, blood running down their faces and on their hands.

"I didn't know what had happened. We thought it was a derailment or a power surge."

He climbed down onto the tracks and walked 200 yards along the tunnel to the stricken train.

A firefighter helped him scramble into the carriage where the blast occurred.

He said: "As I arrived it was obviously a bomb. The roof had blown off."

He added: "I've never worked in conditions like that. We were on a train. It was pitch black. There was smoke everywhere and the smell of burning. We were working by torchlight. The floor was blown away. People were screaming and moaning. There were dead bodies and limbs blown off. The site was slippery from blood.

"I've seen a lot in my time as a paramedic, people under trains, but I'd never worked in those conditions, with only a torch to identify who was injured, not knowing if there might be another explosion, worried if it was a dirty bomb, wondering if you're going to get home."

But his years of major incident training kicked in. Assisted by a doctor who arrived by air ambulance, he treated three critical casualties while on the train, including a woman who was unconscious, a man whose leg had been blown off and another woman who lost both her legs.

All three were taken to the Royal London Hospital, where they remain in a stable condition.

Once the casualties were off the train Mr Treacy and fellow ambulance personnel were asked to clear the scene for safety reasons and to allow police investigations to begin, and he was redirected to Russell Square where he operated an emergency point, treating the wounded, before finally returning to his base.

He said: "Right away, my next call that afternoon was a man with a fishbone stuck in his throat. That brings you back to reality. Work goes on. Life goes on."

Mr Treacy said: "At the end of the day it's what we're paid to do in the emergency services. The people I think are heroes are the members of the public who stayed down there on the train with the injured until we arrived. I'm not sure I could have done that, not in those conditions, but I met at least three who stayed. I'm only sorry I never got their names."

His wife, Peta, said: "Whatever he says, I'm extremely proud of my husband. I know how good he is. People are alive because of him."