Rescuers on Tuesday pulled three people believed to be the last survivors from the wreckage of Japan's worst rail accident in four decades, and raised the death toll to 73 as they found more bodies inside twisted metal train cars.

The seven-car train was packed with 580 passengers Monday morning when it jumped the tracks near this Osaka (search) suburb and plunged into the first floor of an apartment complex. More than 440 people were injured.

Nineteen-year-old college student Hiroki Hayashi, weak and injured in the leg, was extracted from the wreckage after surviving the night with the help of an intravenous drip and drinking water. Two other people were rescued early in the early hours of Tuesday, the Amagasaki Fire Department said.

Semiconscious when taken to the hospital, Hayashi was in serious condition and in intensive care, a Kansai Rousai Hospital official said on condition of anonymity.

Police at the crash site said there were other people still stuck in the cars, but none were responding, indicating Hayashi was the last one alive.

Two of the train's five derailed cars were shoved inside and flattened against the wall of the building's first-floor garage, complicating the rescue.

The authorities, meanwhile, launched their investigation as about ten inspectors arrived at the scene to examine the rail tracks.

The probe focused on whether excessive speed or the actions of the inexperienced, 23-year-old driver caused the crash in an urban area near Amagasaki, about 410 kilometers (250 miles) west of Tokyo.

Hayashi had called his mother after the crash on Monday from a cellular phone saying he was in pain.

"I'm in pain, I can't take it anymore," he said, Hayashi's 18-year-old brother Takamichi told The Associated Press. Takamichi, 18, made the rounds of the area's hospitals Monday night looking for his brother.

Rescue teams said Hayashi had been losing consciousness during the night, but they gave him an intravenous drip and urged him to hang on.

Relatives of those who died were struggling to comprehend their loss.

"I only saw him the night before," Hiroko Kuki, whose son Tetsuji died in the crash, told NHK. "I wish he were alive somewhere... I wish it were only a nightmare."

Monday's accident occurred at a curve after a straightaway. Passengers speculated that the driver — who was still unaccounted for — may have been speeding to make up for lost time after overshooting the previous station.

A crew member aboard told police later he "felt the train was going faster than usual," public broadcaster NHK said, echoing comments from passengers who told the network that the driver seemed to be trying to make up for lost time after overshooting the previous station by 8 meters (25 feet) and then having to back up. The train was nearly two minutes behind schedule, company officials said.

The driver — identified as 23-year-old Ryujiro Takami — had obtained his train operator's license in May 2004. One month later, he overran a station and was issued a warning for his mistake, railway officials and police said.

They were investigating the case as a possible professional negligence on the train operator, West Japan Railway, Co. (search), a prefectural police spokesman said on condition of anonymity.

The accident was the worst rail disaster in nearly 42 years in safety-conscious Japan, which is home to one of the world's most complex, efficient and heavily traveled rail networks. A three-train crash in November 1963 killed 161 people in Tsurumi, outside Tokyo.

Deadly train accidents are rare in Japan. Five people were killed and 33 were injured in March 2000, when a Tokyo (search) subway hit a derailed train. An accident killed 42 people in April 1991 in Shigaraki, western Japan.

An earthquake in 2004 caused a bullet train to derail — the first since the high speed trains went into service 40 years ago.