Federal investigators are trying to determine whether problems found with a signaling system could have contributed to the crash. 联邦调查人员试图确定是否已发现的信号系统的问题能导致所发生的相撞事故。
At the inquest, the accident was imputed to a mechanical failure of the signalling system. 经调查,这次事故被归咎于信号系统中出现的一个机械故障。