by misfortune

例句：

1. 1. He was by misfortune caught in a traffic jam.
   他不幸地被堵在交通堵塞中了。
2. 2. The accident happened by misfortune.
   这场事故是不幸发生的。
3. 3. She decided to move out of town by misfortune.
   她决定因不幸而搬到城外去。