Passenger car
At 1:45 am, the train entered the Nainaibao tunnel at a speed of . After passing the tunnel curve, the driver Wang Mingru discovered that the building near the tunnel exit had collapsed and the light reflections from the rails were missing from the Liziyida bridge. He tried to make an emergency stop, but failed due to steep gradients of the rail before the bridge (at 14‰). As a result, the two diesel locomotives, baggage car No. 13, post office van No. 12, and passenger car No. 11 fell into the river. Passenger car No. 10 and No. 9 crashed into the river bank. Passenger car No. 8 derailed in the tunnel and overturned outside of the tunnel exit.