carelessly

He carelessly tossed his cigarette into the dry grass, starting a forest fire.

(Chinese) 他粗心地将烟头扔进枯草丛，引发了一场森林大火。

The expensive vase was broken after being handled carelessly by the movers.

(Chinese) 那个昂贵的花瓶在搬运工粗鲁搬运后破碎了。