Two people have been killed after a 165ft (50m) crane collapsed onto a block of residential flats.
The crane collapsed on a development. Picture Pablo Behrens
One of the men that died at the block in Battersea, south-west London, was the crane driver and another is thought to be a man washing his car.
The flats have been evacuated but police said no-one inside was injured.
The two-storey building is on the edge of a construction site. Local residents described the collapse as like a bomb going off.
Police, ambulance staff and firefighters were called shortly before 1800 BST on Tuesday to the site in Battersea Park.
Local resident Ron Brown said: "I just heard a massive bang and I thought a bomb had gone off. Then I saw loads of dust go up.
"When I got round to where it had happened I saw the front end of the crane had hit a block of flats and before I knew it the emergency services were crawling all over the place.
"When I went past the building that was damaged all the windows were blown out."
Tony Ddumba, 16, said he was talking to the local man who died just moments before he was crushed by the crane.
"I saw the stones falling first and as they fell down, I saw the crane wobbling and I thought something was going on," he said.
He said he had run one way and the man, who had been washing his car, had run in the other direction. The crane landed just feet from him, he said.
"I was so lucky, it was a miracle," he said.
Joanna Herrera, who was led to safety after the crane collapsed, said: "I was sitting at home when there was a huge bang. I went outside.
"There was a guy on top of a crane and a guy washing his car. All you could see was his leg underneath."
She said a number of residents had complained to the council earlier on Tuesday about the proximity of the building site although Wandsworth Council could not confirm this.
A spokesman said 25 flats and maisonettes on the Patmore Estate had been evacuated.
In a statement construction company, Barratts, said it was co-operating with the investigation authorities.
"Our own health and safety team and a senior management team, are present on site," he said. "We will also be carrying out our own investigation."
The Health and Safety Executive has begun and inquiry in to how the crane collapsed.