Even if we help them, the catastrophe will repeat
The earthquake's effect as been enhenced by low-quality constructions and poor quality of the concrete roads, not to mention that during a quake, the chance of being killed by the quake itself are near to zero, what kills peoples most is the falling buildings caused by the quake. They even had a minimum construction quality to respect in order to reduce effects of the earthquake and they had the means to respect the minimum quality necesary, but they didn't made it has they should.
As a result the effects of the quake where dramaticly enhenced and that's the main reason why the quake did so much damage. And now with all the financial support they got, they could build it in a safe way, but no, they build it the exact same way it was before, so at the next quake, the same disaster will without a doubt repeat itself.
Think I'm wrong? Well think about this: San Francisco, the well known hometown of the golden gate, is almost as dangerous as Haïti when its about quakes, however, emergency procedures, preparations regarding the quakes and parasismic structures alowed to reduce the effects of the quakes. As an exemple, in 1989, San Francisco was victim of a 6,9 quake (almost as high as Haïti's quake), but all the precedures regarding the quakes alowed to reduce the amount of victims to 75, wich is pretty low if you consider San Francisco's high population. Haïti had the means to do the same preparations for the quakes, but they didn't did it, and now see what happened to them.
So instead of donating, try to make them understrand that if they wan't to stop things like that to happen, they had to do what they have to do for it, and they have the means to. And if they don't do it, then all the donations will be wasted cuz the same disaster will happen again, again and again.