Bombers Strike London at Rush Hour

The first explosion occurred at 8:51 a.m. in the front car of a train in a tunnel between the Liverpool Street and Aldgate stations near the heart of London's financial district, known as the City.

Five minutes later, a second blast tore through a train between the King's Cross and Russell Square stations, about two miles to the west. And 21 minutes after that, a third bomb ripped open a train pulling into the Edgware Road station farther to the west, where it collided with two other trains. Witnesses said a huge hole opened in the floor of one car and that one man was sucked out through the opening.

John Simpson, a banker from Gloucester, who was on his way to Aldgate on the first train that was hit, recalled being blinded by a shining light before the blast hit him. "It shook me up and I thought I was on fire," he said after his release from a hospital. "I tried to put myself out. There were a couple of people with head injuries in my carriage. One of the drivers of another train came out and let us all out the back door. There was quite a few people lying on the track. I would say they were dead."

Officials said that preliminary counts showed the first and third blasts killing seven people each and the second causing 21 fatalities. Officials warned that the toll would probably rise overnight. Hundreds more people were injured.

Ever since the train bombings in Madrid that killed 191 people in March 2004, the emergency services here have redoubled their preparations for a similar attack, and on Thursday they quickly launched a preset operation.

Officials rushed more than 100 ambulances and other emergency vehicles to the three scenes, ferried survivors to safety above ground and then rushed the injured to one of a half-dozen designated hospitals. But some witnesses said rescue operations were delayed for critical minutes at some sites because officials feared further blasts.

Gareth Davies, medical director of the London Air Ambulance, said he got to the Aldgate site at 9:10 a.m. "There were lots of walking wounded outside the station," he said. "There were others in the foyer. The more severely injured were on the track and in the wreckage. It was quite overwhelming, it shocked everybody who was in the area, but there was efficiency -- there wasn't much noise."

The authorities shut down all London Underground subway trains, which normally carry 3 million people daily. But they allowed buses to continue running.

Then, exactly 30 minutes after the Edgware Road attack, a fourth bomb went off in the upper section of a packed double-decker bus in Tavistock Square, in the city's Bloomsbury district.

"Everybody ran for cover in a shop doorway," Sandra Pollins, who was on the street near the bus, told ITV News channel. "It was terrifying. It took a minute or two to compose ourselves, then we came out. I could not even recognize that it was a bus. The whole roof had been blown off. There were people just walking around with blood all over their faces."

Officials early on put the death toll there at two, but Laurence Buckman, a physician who treated victims at the scene, said he was told that at least 10 people had died and that several others had suffered life-threatening injuries. Some of the most badly injured had been pedestrians rather than passengers, he said.

The bus driver, who was shaken but uninjured by the blast, told Buckman that the explosion occurred near the rear of the vehicle's upper deck. A suicide bomber could probably have caused more casualties by detonating the bomb on the lower deck. An alternative theory was that the bomb went off by accident while being carried by an attacker. Police declined to comment on the placement of the bomb.