assistant operator, was operating under Ko's supervision. Lee was driving at the time of the accident, but was seated in the left of the cabin and could not see the signals, which were on the right and were obscured by the long hood of the vehicle. According to procedures, Lee had to rely on Ko to relay him the status of the signals. Ko, speaking at an inquest following the accident, stated that he had felt dizzy and could not recall what colours the signals displayed. The advance warning system (AWS) of locomotive L57, which would have automatically halted the train, was switched off. KCR officers in the control centre saw the impending collision but could not warn the crew as the L57 radio was switched off. On 17 September 2019 at 08:32, East Rail service L094 carrying around 500 passengers derailed while approaching Platform 1 of Hung Hom station, injuring eight passengers, with five of whom hospitalised. Cars 4 to 6 were derailed, with cars 4 and 5 disconnected, while cars 1-3 and 7-12 remained on the track. An independent investigation by the Electrical and Mechanical Services Department revealed the cause of the derailment to be a widened track gauge due to the deterioration of the railway sleeper. Sleepers (35-36) of turnout P5116 were found to have been rotted and the screw hole deformed and enlarged. This significantly weakened the ability of the sleepers to be secured to the baseplate and thus maintain proper track gauge. In addition, under the dynamic stress load of the train running over it, the track widened excessively. Sections of the track, including check rails, were found broken and cracked. It was found that four earlier trains that entered Hung Hom station on that morning before service L094 had also suffered hit marks on their wheels. Track sections between 17 sleepers in turnout P5116 exceeded the safety limit of 1,455 mm (the designed track gauge was 1,435 mm). The investigation recommended the installation of real-time monitoring equipment to improve the surveillance of track conditions so that an improved maintenance regime could prevent similar events from occurring in the future. Underframe cracking On 21 December 2005, a Metro Cammell EMU failed while in operation. Following examination of the train, KCRC staff detected minor cracks in the welding of mounting brackets for some underframe components. A review panel commissioned by KCRC looked into the problem from