"There was no way to escape. People were waiting outside - if someone tried to jump out, they would attack them with machetes."
Of the 36,000 runners lining up in Sunday's London Marathon, 33-year-old Burundian Olympic hopeful Gilbert Tuhabonye has perhaps the most remarkable story.
In 1993, Tuhabonye, then 19, was looking forward to graduating from his high school in Kibimba and taking up an athletics scholarship at Tulane University in America.
But one October day, Tuhabonye and 100 of his fellow Tutsis were captured by rival Hutus, herded into a petrol station and set on fire.
"They were doing everything they could to make sure everybody in the building died," says Tuhabonye.
He was the sole survivor of the massacre as he smashed a window, climbed out and ran for his life.
Eventually he found safety in a hospital and began the slow recovery process.
Miraculously, less than 18 months after having the flesh burnt off his right shin down to the bone, Tuhabonye was running again, competing at the 1995 World Student Games in Japan.
The following year, as one of Burundi's most promising young talents, he was selected to go to an International Olympic Committee training camp for athletes from developing nations.
It was the greatest moment of my life. If I can let someone who tried to kill me go free, I can do anything - it inspired me."
There, in a gesture of greater symbolism than the organisers could possibly have imagined, Tuhabonye carried the torch for the Atlanta Olympics on the relay through the streets of Birmingham, Alabama, the birthplace of the civil rights movement.
"That fire had been burning me, but now I had it in my hand - it was amazing," he said.
"They told us to go slowly, but I didn't listen to what they said - I was running so fast. It was an unbelievable feeling." In 1996, Tuhabonye came face to face with one of the people who tried to kill him.
"He collapsed at my feet, begging forgiveness," he said.
"Here was the guy who was in charge of putting everybody in that building. Some of my friends were approaching, and I knew that if I didn't let him go, they would kill him. So I said 'Go, get out of here.' He couldn't believe it.
"As I watched him go, it was the greatest moment of my life.
"If I can let someone who tried to kill me go free, I can do anything - it inspired me."
Now settled in Austin, Texas, Tuhabonye has become something of an inspiration himself to hundreds of runners who are part of his running club, Gilbert's Gazelles.
And coaching them led to the former middle distance runner stepping up to marathon running.
Tuhabonye now runs a thriving running club in Austin, Texas
"In 2001 I was coaching a lot of people at distance running. I'd run with them for two hours or so, and it was pretty easy.
"One day I did 30km on 5:10 mile pace, so I thought, 'Maybe I should do a marathon'.
"In my first race I ran just over five minutes a mile pace until 23 miles, but failed to drink any water and so had to walk the last three miles. But it gave me hope that I could be a marathon runner."
Going into the London Marathon, Tuhabonye's personal best is two hours 22 minutes and seven seconds.
That is four minutes outside the 'B' standard qualifying time for the Olympics and seven minutes off the 'A' standard.
"If I could get to Beijing it would be a tremendous message about forgiveness," he says.
"I've moved away from the past and forgiven the people who tried to kill me. For the world to be a better place, we have to leave the past behind and move on."
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