Why has such misfortune befallen me .

为什么这样的厄运会降临在我身上。

The greatest disaster that has ever befallen us .

我们遭受的最严重的灾难。

I know not what has befallen them .

我不知道他们遭遇了什么。

Some misfortune must have befallen him .

某种灾难必降临在他头上了。

If we had been careful such a calamity would not have befallen us .

假如我们谨慎的话,这种灾难不会降临到我们的头上。