The collision occurred during rush hour, at about 19:00
CST on the
Changping line in Beijing. Another train, SFM93 set CP059, experienced skidding due to snowfall at
Life Science Park station, the signalling system experienced a downgrade to manual, non-
CBTC mode. As a result, CP024 stalled and waited in front of a signal behind CP059. CP032, which was manually driven, departed
Xi'erqi station and at a speed of . CP032 performed an emergency stop but failed to stop on the slippery track and hit CP024. A statement by the Beijing Municipal Commission of Transport indicated that the CP032 was travelling downhill and could not brake effectively.
Beijing Subway later said that CP024 had become separated at several carriages, and the front two cars of CP032 involved in the collision had detached. == Aftermath ==