The MTR Corporation has launched an investigation after part of a train derailed at the Chai Wan depot on Thursday morning. The Island Line train, carrying no passengers, had just completed service and was entering a track in the depot at 1.10am when its third car derailed and damaged some stairs next to the track. No one was injured. In pictures taken at the scene, the stairs appeared to have been lifted off the ground. The car was also damaged. An MTR spokesman said in a statement that the wheels on a bogie on the third car were found to have “shifted out of position”. “Depot engineers subsequently observed that the car body and bogie of the train car concerned were slightly damaged, and a staircase at a berth was displaced,” the spokesman said. MTR Corp was investigating, and looking particularly into the condition of the track and its interaction with the train’s wheels, the spokesman said. Service on the Island Line on Thursday was not affected. The Electrical and Mechanical Services Department said its investigators found that the wheels on the bogie on the third car had derailed. The cause of the incident had yet to be confirmed, a spokesman said, adding that it had requested the MTR Corp submit an investigation report in four to six weeks. He dismissed speculation that leaks or explosions in suspension airbags underneath the third car had triggered the derailment. Hong Kong MTR to launch independent probe into 10-hour service disruption A source with knowledge of the case said the incident could have occurred due to incompatibility between the wheels on the car and the track. Kwai Tsing district councillor Leung Chi-shing, also an MTR train operator since 1984, said a derailment involving an MTR train was very rare, and he had never seen one in his more than 30 years of service. In January 1994, a compartment of an eight-car MTR train derailed at Kowloon Bay station. No one was injured. The case was reportedly the first of its kind in MTR history. “It was lucky that the incident didn’t take place when the Island Line train was in service, as the consequences could have been unpredictable if it was,” Leung said, adding that it was also lucky that no one was on the staircase, which was used by MTR personnel to get on or off trains at the depot.