昨天的火灾是一起严重的事故。

Yesterday's fire was a serious ___incident.

警方正在调查昨晚发生在市中心的暴力事件。

The police are investigating the violent ___incident that happened downtown last night.

电梯故障只是一个小插曲，很快就修好了。

The elevator ___incident was just a minor hiccup and was fixed quickly.