TOKYO, April 25 -- Rescue workers struggled for more than 11 hours to free survivors of a packed commuter train in western Japan that derailed and smashed into an apartment building toward the end of the morning rush hour on Monday, killing at least 73 people.
An estimated 340 people were injured in the crash, the nation's worst train disaster in four decades. Officials said at least four survivors were stuck in the seven-car train's first car, which was wedged deeply into the building.
Ambulances, paramedics and police surrounded the crash site near the city of Amagasaki, about 250 miles west of Tokyo.
Five of the train's cars derailed around 9:18 a.m., with two of them crashing into the apartment building. The train carried 580 passengers and might have been traveling faster than the 43 mph speed limit in the zone, officials said.
The front facade of the apartment building partially collapsed from the impact of the crash. The twisted hulk remained stuck in the structure as rescue workers sifted through the rubble for survivors. Witnesses said that several of the injured appeared to be high school students and that a shortage of stretchers was causing rescuers to remove train seats and use them to carry the injured.
Masato Koyama, an announcer for Japan's NHK television network who happened to be on the derailed train, told reporters that "about 9:18, the train put on the brakes and suddenly my body was flung forward along with other passengers. When I rose, someone was bleeding from head, another bleeding from arm and other people were not moving."
Investigators said that the cause of the crash was uncertain but that excessive speed or the actions of the inexperienced driver -- a 23-year-old who had been on the job for 11 months -- might have contributed to the disaster. The driver had overshot the stop lines at the station before the accident site, causing a brief delay. Some witnesses told local TV stations that the train was moving unusually fast, perhaps to make up lost time.
Earlier reports from the scene indicated the train might have hit a car at a railway crossing before derailing. But West Japan Railway Co. officials told reporters it had not yet been determined whether the train hit the car before or after derailing.
"There are many theories, but we don't know for sure what caused the accident," said Hiroyuki Hosoda, the chief government spokesman. "The prime minister instructed us to respond with urgency."
Railroad officials told the Kyodo News Service that grinding marks were found on the tracks, sometimes an indication of a train running over an object such as a stone. But there was not yet enough information to draw a connection to the crash, the officials told the news agency.
The train's driver remained in serious condition at a local hospital.
"Our most important task now is to rescue the passengers from the accident, and we are doing our best," the railroad's president, Takeshi Kakiuchi, told reporters.
Japan maintains one of the world's largest, busiest and most sophisticated train networks, yet derailments and serious accidents are rare. Monday's accident marked the nation's worst rail disaster in nearly 42 years. Three trains crashed near Tokyo in November 1963, killing 161 people.
