London

Three bombs went off within fifty seconds of each other on Underground trains at Aldgate, Edgware Road and Russell Square, in the middle of the morning rush. A fourth was detonated on a bus in Tavistock Square an hour later.

Fifty-two people were killed and around seven hundred injured.

The deep tunnels filled with smoke and dust in the dark. Passengers in the carriages behind forced doors, walked the live rails, and carried people out. Underground staff went back down into the tunnels repeatedly.

An off-duty officer of the City of London Police and a doctor from a nearby surgery went into the Aldgate train and worked in it.

The city ran its own rescue for the first half hour, because that was how long it took anyone to understand what had happened.