The Haitian Blogger echoes others' description in saying that the mountainous areas are totally wrecked, and that the structures have just slid down onto each other:
All the poor living on the mountains, in houses build on the mountains, feared suffered heavy, heavy casualty. Our report is that these houses on the mountains tumbled down, one on top another.
A terrible situation! Devastating. There's NEVER been an earthquake of this magnitude in Haiti. Major aftershocks happening…
Someone in Haiti said to me "The are of Kafou is destroyed…the population of Port au Prince has just been REDUCED, don't know by about how much. Everyone, rich and poor, build on the mountains, all the mountains are down! This is going back to the ground zero."
The Dish 