fortunately

I forgot my umbrella, but fortunately it didn't rain until I got home.

(Chinese) 我忘了带伞，但幸运的是直到我回家才开始下雨。

Fortunately, the firefighters arrived quickly and saved the building from burning down.

(Chinese) 幸运的是，消防员赶到得很快，保住了那栋建筑没被烧毁。