LONDON - Two people were killed on Wednesday when a helicopter hit a crane at a building site in central London during morning rush hour and plunged to the ground in a ball of flames.
Police said at least 13 people were injured after the aircraft smashed into a crane on the top of an unfinished luxury apartment block at Vauxhall, near the headquarters of the MI6 foreign spy agency on the south bank of the River Thames.
The top of the 51-storey building, The Tower at One St George Wharf, was shrouded in mist at the time. Police have ruled out a terror attack.
Witnesses said part of the crane fell on a street below sending construction workers fleeing for their lives, while the helicopter, spewing a thick plume of black smoke, cast burning wreckage over the ground.
Firefighters said they rescued a man from a burning car. An AFP reporter later saw a charred vehicle lying alongside a pile of twisted metal from the helicopter, just metres from a major train line.
Commander Neil Basu of the Metropolitan Police said it was "something of a miracle" that more people had not died given that the crash occurred in a busy residential and business district at rush hour, around 8am (0800 GMT).
He confirmed that the pilot, believed to be the only one in the helicopter, had been killed along with a person on the ground.
Emergency services said six injured people were taken to hospital, five with minor injuries and one with a broken leg, while seven others were treated at the scene, which is near the site of the new US embassy.
"There was a flash and the helicopter plunged to the ground. It exploded and you can imagine the smoke coming out of it," said eyewitness Paul Ferguson, who was working in an office near the tower.
"It may be that on this misty morning the lights on nearby St George's Tower weren't on and it moved and clipped the edge of the crane and lost control," he told BBC News.
The Air Accidents Investigation Branch is now looking into what happened, including suggestions that the crane did not have its aircraft warning light on.
London Fire Brigade said more than 50 firefighters were working to secure the rest of the damaged crane after putting out the blaze in around 25 minutes, but said there was no risk of it falling.
Several construction workers said they had heard that crane operator had been running late and was only halfway up to his cabin when the aircraft hit.
Witnesses said part of the crane crashed into the street below the tower, which is due for completion later this year.
Paul Robinson, 42, had been waiting to get onto the building site in his rubbish truck when he felt something hit his vehicle.
He thought the truck driver behind had driven into him. "Then I looked up, saw debris falling and ran like hell," he told AFP.
Looking back, "I saw the crane, the boom, hit the ground. It made a big bang."
The street was empty at the time, he said, but "if it was 30 seconds later, there'd have been cars there".
Local resident Nic Walker, 35, said he had been in bed when he heard a helicopter flying overhead, followed by "an almighty crash".
"I knew immediately what had happened -- it's extremely foggy this morning," he told AFP. "I put on some clothes and rushed outside to see if anyone needed help. There was burning fuel everywhere."
The crash caused gridlock on the city streets and temporarily shut down several train, bus and Underground stations in the area.
Prime Minister David Cameron paid tribute to the emergency services for their "rapid and professional response".