Hong Kong’s embattled government is to investigate whether Tuesday’s derailment on the East Rail line was sabotage.
As the mystery over the cause of the accident deepened, one line of inquiry turned to whether disgruntled MTR Corporation employees were behind the incident.
“Many possibilities have already been ruled out after further checks, so the Hong Kong government will look into whether the derailment was an inside job,” a source said.
“So far, the MTR Corporation still has no clues about the probable cause of the incident.”
The Electrical and Mechanical Services Department (EMSD) said it would examine various factors, including the mechanical parts of the train, the track and associated devices, as well as the possibility of obstruction by foreign objects.
It also emerged on Wednesday that a fourth crack had been found on tracks at the scene of the city’s most serious rail accident in more than two decades.
Five passengers were sent to hospital, and 500 others were left in shock, after the 12-carriage train derailed as it entered Hung Hom station at around 8.30am. Three carriages veered off the tracks at a junction where trains are directed to different locations.
Services on the East Rail line, the city’s only local line connecting it to the border with mainland China, were disrupted for most of the day.
The cause of the derailment was not yet known, although the rail firm and the government, which is a major shareholder, have vowed to conduct a thorough investigation.
Transport minister Frank Chan also said nothing was being ruled out, but police have said they found no suspicious objects at the scene.
Cheung Kim-ching, chief engineer of railways at the EMSD, said on Wednesday that part of the track was completely torn apart by the fourth crack, where there were two fractures measuring 30mm and 45mm in width.
It followed the discovery of three cracks on the track on Tuesday, two of which were each about 30mm wide.
“It will be one line of inquiry. We will invite experts to examine the material on whether the cracks were the cause or the result of the incident,” Cheung told a radio programme.
In a statement released on Wednesday night, the EMSD confirmed it had not found any foreign objects on the section of track.
“The department is deeply concerned about the serious incident … It will conduct an independent, thorough and in-depth investigation, and seek advice from overseas experts,” it said.
Former railway chief and lawmaker Michael Tien Puk-sun said originally he suggested a malfunctioned railway switch lock at the diverting point could have caused the incident.
“I raised this with the MTR, but after checking, they confirmed the lock functioned properly so this possibility was ruled out,” he said.
The wreckage of the derailed carriages had been cleared by morning, while one track remained closed and blocked off with orange netting. The derailed train was stationed at the closed Hung Hom-Lo Wu platform.
The rail operator was expected to be fined HK$25 million (US$3.2 million), the maximum financial penalty available, for Tuesday’s service delays, according to lawmaker Ben Chan Han-pan, who heads the legislature’s transport panel.
About 200 staff worked overnight to remove carriages and carry out safety checks and repair work.