Father of three Kiran Patel said he felt “lucky to be alive” after a fire broke out near Elephant and Castle train station.
The local described a “massive boom” after an explosion at a garage just metres from where he was standing.
Mr Patel, 55, told the Standard: “There was a massive boom and then a wall of heat hit me like I have never experienced before. It was like someone had opened an oven in my face.
“Everybody was scattering running for their lives I thought I was going to die, I thought of my family.
“The police told us to run it was like something I would imagine out of a terrorist attack. I’m lucky to be alive, there was panic in people’s eyes.”
Mr Patel said emergency workers had told him the fire and explosion could have been triggered by a generator in the garage.
He added: “From what they were saying they were talking about the generator as a possible cause. It’s incredibly that it looks as if no one was killed. I will play those scenes back in my mind though.”
A huge cordon remains in place around the blaze scene.
Fire investigators are trailing for clues as to how the fire started in the charred remains of the garage.
Road closures have cause traffic jams around the area for commuters. However Elephant and Castle station is now open.
Dramatic photographs have flooded social media as the incident was unfolding on Monday around 1.45pm.
A massive plume of black smoke could be seen rising across the capital’s skyline.
Ten fire engines and 100 firefighters were on scene to tackle to blaze.
Six people were treated at the scene by London Ambulance Service crew and one of those people was taken to hospital.
Underneath the railway arches three commercial units, four cars and a telephone box had caught fire in the incident, London Fire Brigade confirmed.