I don't know the square miles, but the earthquake leveled their capital city which was heavily populated largely with people who live very poor, marginal lives. They didn't have much to start with and now they have nothing, not even their families. That has to be a crushing blow to a people who value family over just about everything.
I heard someone comparing this with the Tsunami the other day and I thought, "Yeah and that was really terrible, but most of the people in that event were either alive or dead. In Haiti, they're crushed, mangled,burned, torn, buried alive, or, oh yeah, dead." It's just too horrible.