The Joo Koon rail accident occurred on 15 November 2017, when two trains met into accident causing 36 injuries. The stationary train was in the process of being detrained due to a train fault. This incident is the second train collision in Singapore MRT's history, after the Clementi rail accident in 1993. Both trains were operating under the recently installed Thales SelTrac CBTC signalling system at time of incident, and the Minister of Transport Khaw Boon Wan expressed that he was "disturbed" by an initial finding that a "critical safety software" was inadvertently removed from the stationary train, possibly due to a malfunctioning signalling circuit, had led to the accident.