The lorry ran into the back of the rearmost car in the queue which bumped into the car in front, which then hit the next one, and so on in a chain reaction.

那辆卡车撞到了队伍中最后面一辆汽车的尾部，汽车又冲撞到前面的汽车，前面的汽车又碰撞到了再前面的，这形成了连锁的反应。