The money will be used to help the people ------lost their h

是who 啊~
定语从句的意思就是用一个句子去修饰一个词,这里背修饰的是people,也就是people lost their homes,所以修饰人用who 指代people就可以了~
而你说的whose,我举个例子,Mr.Liu wants to talk to the students whose homework has not been handed in.这里是指,students's homework has not been handed in,whose指代students'这个所有格.
能发现区别了么?
如果你说的那句话用whose的话,应该后半句是whose home was ruined in the tsunami.
不知道有没有说清楚哈~