|At 0947 a blast tore through a number 30 double-decker bus at the junction of Tavistock Square and Upper Woburn place.
It was travelling from Marble Arch to Hackney but had been diverted from its normal route because of road closures in the wake of the tube bombings around an hour earlier.
The bomb, placed on a seat or the floor at the back of the upper deck, killed 13 people, plus the bomber. More than 110 were injured.
One eyewitness said: "It was a massive explosion and there were papers and half a bus flying through the air". Another described how the roof was "lifted lazily forward and a long length of metal spun up twisting in the air".
The bus was outside the British Medical Association when the bomb went off and doctors rushed from the building to provide emergency care to the injured.
In the aftermath a large area was cordoned off and searched while forensic teams combed it for clues.
Police later established that the bomb was detonated by Hasib Hussain, 18.