In this story:

• 60 trains to be idled
• No sign of human error
• Driver unaware train had derailed
• Related stories and sites

ESCHEDE, Germany (CNN) -- While work crews pulled bodies from the twisted wreckage of a high-speed train Friday, German railway officials focused on a damaged wheel that they suspect may have caused the country's worst rail disaster since World War II.

At least 90 bodies have been recovered from the wreckage of the Hamburg-bound InterCity Express, which crashed and broke apart Wednesday morning in this small town 35 miles north of Hanover.

Rescue workers toiling under floodlights in the early morning hours Friday used three huge cranes to lift chunks of a 200-ton overpass that collapsed on the train's carriages when it derailed and hurtled against the bridge at 125 mph (200 km/h).

They found barely recognizable corpses crushed in the restaurant car of the train, and an official said that when the bodies had been recovered, rescue operations would be suspended until morning. They said the site had become too dangerous and that parts of the bridge were in danger of falling.

A spokesman for the rescue committee said rescuers no longer expected to find survivors in the mangled wreckage.

About 200 people were injured, 95 of whom were treated in hospitals, the officials said.

Horst Stuchly, president of the government rail watchdog agency EBA, said it appeared that a rear axle wheel on the carriage behind the locomotive had broken more than three miles (4.8 kilometers) before the train passed over a switch and derailed.

"It looks as if the wheel tore about three to four miles (five to six kilometers) before the scene of the accident," Stuchly told ARD television news. "It appears that the train continued until it reached the switch, where it then derailed."

Stuchly said that the wheel could have been damaged by something on the rail or broken apart because of material fatigue. He also said that a deliberate act of sabotage could not be ruled out, although there have been no such indications.

Deutsche Bahn, the federal railway agency that operates the trains, announced it is taking 60 of its first-generation ICE trains out of service for inspections. The trains are between 5 and 7 years old.

The decision will idle more than half of the nation's high-speed trains.

"It is possible that a defect on the undercarriage played a role in the crash or was even the cause of the crash," said Deutsche Bahn chairman Johannes Ludewig.

Ludewig said the older trains were being taken out of service even though there was no conclusive evidence about the cause of the crash. Another 44 second-generation trains, which were introduced in 1994, will not be taken out of service.

Deutsche Bahn announced earlier that it would cut the speed limit for the luxury trains to 100 mph (160 km/h) from 125 mph (200 km/h).

About 65,000 passengers travel on the 104 ICE trains each day. With more than half of the trains out of service, travelers will face delays and disruptions for several days.

Until Wednesday, the ICE trains had carried more than 133 million passengers without a serious accident since they were introduced in 1991. Ludewig said the first generation ICE trains "traveled more than 1 billion kilometers (620 million miles) without any serious accidents."

He said the trains would not return to service "until the entire undercarriage system has been thoroughly inspected and analyzed."

Stuchly said there was no indication of human error and that part of the train derailed before it reached the overpass. The locomotive separated from the rest of the train at the overpass -- one of the events investigators are considering as a potential cause of the crash.

The weekly Rheinischer Merkur reported Thursday that federal rail experts found signs that one of the coaches derailed fully 3 3/4 miles before the overpass. The newspaper said the section continued along the rail bed until a bend near the overpass.

Police in Celle said parts of a train were found on the track 3 3/4 miles from the bridge, but they gave no details on the parts and were uncertain whether they were from the crashed train.

Officials said it appeared that the fifth car of the 12-car train hit the bridge. The back end of the car was broken off and the fourth car veered off the rails and rolled onto its side, while three other cars jackknifed farther up the line.

The lead locomotive remained on the tracks, and the driver apparently was unaware of the disaster. It came to a stop only after the station master at Eschede activated an emergency brake.

The rest of the train was squashed beneath or against the collapsed overpass. The tracks were strewn with debris -- some from the crash, some created by rescuers ripping apart the wreckage.

The accident was the worst in Europe since 1974, when 153 people were killed in Zagreb when a train bound for Germany from Belgrade derailed.

It was the worst in Germany since June 1945 when 102 people were killed when an American troop transport train crashed into a train carrying German war prisoners near Munich.

Also Thursday, the Japan Railway Co. spokesman said the company has begun an inspection of its bullet trains and sent a representative to the accident site in Germany.