I didn't mean to break it— it was an accident.

我不是故意打碎它的—这是个意外。

《牛津词典》

Yes, I know it was an accident, but that's beside the point.

是的，我知道那是个事故，可是这无关紧要。

《牛津词典》

He was quite angry with the driver because his car hit his brother, even though it was an accident.

他对司机相当生气，因为司机开车撞到了弟弟，尽管这只是一场意外。

youdao

In other words, this was not meant to be a record to be left for the future. It was an accident.

换句话说,这些并不是刻意为将来,留下的记录,只是个意外而已

耶鲁公开课 - 古希腊历史简介课程节选

"I was hopeful it was an accident and not a deliberate act, " Mrs Heaton added.

BBC: Manchester

But Mr Dupree has said it was an accident and he acted in self defence.

BBC: Murder accused Raymond Dupree had 'no memory' of glassing

What happened I will explain in time but put it this way, it was an accident and I panicked.

BBC: Tia Sharp murder trial: full Stuart Hazell letter