An early investigation blamed the signal system failure on a loss of power.

初期调查是归咎于停电造成信号灯故障。

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Tuesday's crash occurred at about 14:51 local time (06:51 GMT) following a signal system failure at a subway station on Line 10, Shanghai Shentong Metro Group said.

星期二的追尾事故大约发生在当地时间14：51 (06：51 GMT)，当时的地铁10号信息系统失灵。

youdao

The first indication is that Tuesday afternoon's crash occurred after the metro system staff had switched to manual scheduling following a signal failure.

暗示星期二下午这场事故发生的第一个信号就是，地铁系统员工在信号指示失败后立刻转为手动操作。

youdao

But investigators are focused on a failure of the train tracks themselves, as opposed to an error by engineers or a failure of the train's signal system.

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