It's hard to say what caused the accident.

很难说造成事故的原因是什么。

《牛津词典》

The accident was caused by negligence on the part of the driver.

事故是由于司机的过失造成的。

《牛津词典》

The accident was caused by pilot error.

这场事故是飞行员的失误造成的。

《牛津词典》

Clemente continued to improve. He had suffered for years from pain caused by an automobile accident.

VOA: special.2010.04.11

There was some evidence the explosion was caused by an accident in the ship's fuel tanks.

VOA: special.2010.07.08

It can be caused by a car crash, a fall or a sporting accident.

VOA: standard.2010.05.25

The Google car has logged 100s of thousands of miles on public roads with no computer-caused accident (they did have a human rear end them once).

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Independent reports by military aviation experts, a fatal accident inquiry in Scotland and other investigations had all concluded that there was no conclusive proof of what caused the accident, he said.

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He added that a fire investigation had concluded the blaze was probably caused by accident.

BBC: Appspond Lane blaze: Fire crews still visit