I lost my watch because of carelessness.

我由于粗心而丢了手表。

youdao

She has just lost her job because of carelessness.

她刚刚因疏忽大意而丢了工作。

youdao

Because of carelessness, he incurred large losses.

由于不小心，他遭到了极大的损失。

youdao

One outgrowth of this kind of carelessness was the rise of opportunistic thieves who especially targeted security complexes because they know people living there were, ironically, so utterly unconscious of security once they were inside the perimeter of the keep.

CNN: Pistorius, and the psychology of walls