A suspect who police said had a history of mental illness was under interrogation in Daegu, South Korea's third-largest city, but police still did not know what motivated the attack. Rescue workers had given up the search for survivors by the afternoon, and many of the 138 injured were seriously hurt.
The fire started in a six-car train at a station, igniting seats and spreading to another train also stopped at the station, officials said. The fire killed people by the dozens, burning its victims or asphyxiating them with deadly fumes.
Fire department and local government officials said they estimated the death toll at 120 by combining the police tally of 52 dead with another 70 bodies counted on one of the two trains destroyed in the blaze.
Many of the bodies were burned beyond recognition, however, and officials said they would have to wait for DNA tests that could take weeks to determine an exact number.
``The total death toll is expected to rise to about 120. We believe the death toll will not rise drastically from that,'' said Lim Dae-yoon, the chief of Daegu city's east district municipal government.
Firefighters gave horrifying accounts of the scene underground. Many bodies were found on the subway stairs, where people apparently choked as they tried to escape. On the platform and in the train were the ashen bones of those trapped in the flames.
Chung Sook-jae, 54, rushed to the scene after her daughter, 26-year-old Min Shim-eun, telephoned her husband to say she was suffocating. Then the line went dead.
``She never caused any problems. She was a good kid. Why does this have to happen her?'' Chung cried. ``If she's not out by now, she's probably dead. What am I going to do if her body is all burned out of recognition?''
Police were interrogating Kim Dae-han, 56, who witnesses said carried the carton into the subway car, said Daegu police lieutenant Kim Byong-hak. Another police official, speaking on condition of anonymity, said Kim Dae-han had been treated for mental illness in the past.
``When the man tried to use a cigarette lighter to light the box, some passengers tied to stop him. Apparently a scuffle erupted and the box exploded into flames,'' the officer said.
Authorities said that the fire was put out by 1 p.m., about three hours after it started, but toxic gas in the tunnel delayed rescue efforts, the Yonhap news agency said. The acrid odor of burned plastic still wafted over the fire scene hours after the flames had been put out.
The television station YTN aired footage of the frantic scene inside a nearby hospital, showing nurses attending to a man who was reportedly the suspect. The man sat frowning on a bed wearing a hospital smock, his face and hands smudged with soot.
Yu Heung-soo, a police sergeant in Daegu, said Kim Dae-han had been burned on both legs and the right wrist. But a doctor told YTN that the man's only injury was toxic gas inhalation.
YTN also reported that the suspect worked as truck driver and had once threatened to burn down the hospital where he had received unsatisfactory treatment. The station did not cite sources.
In the minutes after the fire began, thick black smoke billowed out of the subway's ventilator shafts. Downtown traffic came to a standstill as ambulances rushed to the scene. Firefighters wearing orange suits and oxygen tanks rushed into the subway.
Kim Bok-sun, 45, said her missing daughter, 21-year-old Kang Yeon-ju, was on the burning train and called in panic.
``She only said that there was a fire and the train door wasn't opening, so I told her to just break open a window and get out,'' she said, her voice trembling with emotion. Kim Bok-sun called her daughter back a few minutes later, ``but she never answered the phone.''
Rescuers brought victims, their faces and clothes black with soot, up to the street in stretchers and slid them into ambulances. One witness recounted the terrifying scene inside the subway as the fire ignited.
``The man kept flickering a lighter and an old man told him to stop. The man dropped the lighter and the train caught fire,'' an unidentified male survivor told YTN. ``Several young men seized him, but the fire spread and black smoke rose. Then everyone rushed out.''
One man told YTN that his friend called on his cell phone and said he was trapped inside one of the cars. The unidentified man told YTN that he had called subway officials and they were unaware of the fire at the time.
President Kim Dae-jung ordered the government to consider designating the accident site as a special disaster zone, which would give it priority in receiving government aid and other assistance.
Daegu, one of the 10 World Cup soccer venues last year, has a population of 2.5 million.
