YILAN, Taiwan (Reuters) - Taiwan President Tsai Ing-wen offered words of consolation on Monday as she met relatives of 18 people killed and 187 injured when a train derailed in the island’s northeast, its worst rail disaster in more than three decades.

Officials said four carriages overturned on Sunday after all eight cars of a train carrying 366 passengers left the tracks on a bend near a railway station in Yilan county, about 40 km (25 miles) from the capital Taipei.

Tsai joined Buddhist monks in prayer before an altar adorned with flowers next to a hospital, while nearby, relatives and friends of the victims wept as they sifted through battered suitcases recovered from the train wreck.

“We are really sorry...You have to stay strong,” Tsai told Chen Yu-chan, 41, whose only daughter, a seventh grader, was killed. “We will do everything we can,” she told another person, who was sobbing bitterly during her visit to the hospital.

Health authorities appealed for blood donations to help treat the many injured people, who included one foreigner, an American. Six of the dead were under 18, officials said.

The disaster was Taiwan’s deadliest rail accident since a 1981 collision that killed 30 people.

The head of the state railway administration, Lu Jie-shen, had offered to resign but this was not accepted by the transport minister, the railway authority said.

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China’s policy-making Taiwan Affairs Office expressed “deep condolences” to the families of victims.

Train services resumed early on Monday after all derailed carriages had been moved to one side of the tracks.

An initial inquiry, conducted by an investigation committee set up by authorities, showed that speeding might be the cause of the accident, the official Central News Agency said.

The agency said the train derailed on a curve while moving at close to 87 miles per hour (140 kmh), above the speed limit of 46 mph (74 kmh), quoting the head of the investigation team, Wu Ze-cheng. Further investigation was needed to determine the cause, he added.

Many of the casualties were in a carriage at the front of the train, said one official, adding that the driver, surnamed You, had been moved out of intensive care, though his condition was still unstable.

“We will ask him what happened after he stabilizes,” said Liu Can-huang, head of the car maintenance unit of the railways.

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The train recorder, which tracks speed, among other data, had been sent to prosecutors to be examined, he added.

The derailment was not expected to cause a major disruption to economic activity.

BRIDE IN MOURNING

But the human tragedy was considerable.

Tung Xiao-ling, 43, sobbed as she told Reuters how she had lost eight of 17 relatives, aged nine to 67, as they returned from celebrating her sister’s wedding.

“No one can accept that one day you are a bride and the next day you are mourning a family member,” said Tung, who was not on board the train.

“I hope they find out what happened as soon as possible. We trusted the safety of Puyuma,” she added, referring to the express train line.

The fastest of Taiwan’s regular trains, the Puyuma Express began operating in 2013 to negotiate the rough terrain of the East Asian island’s east coast.

Hundreds of rescuers and military worked through the night, using spotlights to search the wreckage for survivors, as ambulances waited to take the injured to hospital.

Some rescue workers gave first aid to the injured, while others used cranes to lift some of the battered cars sprawled in a zigzag near the tracks.

“This is something that is not supposed to happen when taking a train,” said Chen Tai-liang, whose niece, a seventh grader, was killed.

“Why did it happen?” he asked, after speaking to the president.