Rescue workers said Tuesday they believe all bodies have been recovered from the wreckage of a three-train crash in south London that killed 36 people and injured more than 100.

Railway officials said Monday's accident near Clapham Junction, one of Europe's busiest rail stations, may have been the result of a signal mix-up caused by work being done on the line.Opposition politicians and consumer groups said lax safety measures and overcrowded trains were underlying causes of the morning rush-hour crash.

A crowded commuter train plowed into the rear of a stationary passenger train. An empty freight train coming in the opposite direction on a parallel track then hit wreckage from the first crash.

More than 110 of the estimated 1,500 passengers on the trains were hospitalized, 32 suffering serious injuries including multiple fractures, crushed abdomens and amputations, hospital and ambulance officials said.

"Bodies were cut in half, limbs were thrown around by the impact," physician Robin Winch said.

Rescuers aided by arc lights and cranes worked until dawn Tuesday to clear debris from the crash, Britain's worst rail disaster since 43 people died when a subway train crashed in a London tunnel in 1975.

A British Rail spokesman who requested anonymity said officials hoped to have commuter trains running again by Tuesday night's rush hour, and at least some trains running through the accident area.

The Duchess of York and Prime Minister Margaret Thatcher separately visited the injured at St. George's Hospital.

Allison Killerby, a 26-year-old clerk who suffered deep gashes across her nose and forehead, recalled:

"I saw people's legs and arms and heard screaming for help . . . In one way I wish I had been unconscious so I wouldn't remember it all so clearly."

Eight of the 20 cars overturned and three were hurled into the air. Some passengers were trapped up to four hours.

Ronald Arlette, 52, who was on the stationary train, said: "There was an almighty bang, like an explosion. The carriage went up and we flew over and over.

The British Railways Board said preliminary investigations suggested the crash may have been due to a signal failure associated with modernization of the line's 40-year-old signaling equipment.