Witness Bill McKinnon, who lives in Didcot near the scene of the explosion, told the BBC: I was sitting in my front room, I can see the power station quite clearly from where I am, it s only about 400 yards away.
About 4 o clock, when I heard the explosion and the very loud rumbling, by the time I had got up and looked out of the window there was a huge cloud of dust which came through and over our village.
When that had cleared I noticed that half of the old power station, where they used to keep the generators, half of that was missing.
There wasn t any physical feeling, it was only noise. When they took down the cooling towers a couple of years ago it was about the same volume as that. It was quite loud.
He added: I was a little bit surprised because normally the contractors let us know when they are going to do explosions, so I was a bit surprised because we hadn t heard anything.
Very shortly afterwards the air ambulance turned up and then fire engines and ambulances started arriving, and a little while after that another air ambulance turned up, and I think they are still there.
Mr McKinnon said the explosion took place in a large building which housed the generators for producing power.