I believe the number will be higher too. News reported even the Presidential Palace and UN buildings collapsed. So I don't think there're buildings designed to withstand earthquake. I doubt there's any organised effort to rescue whoever trapped under collapsed buildings too.
The toll will be tremedous, but ironically, one reason there might be less deaths than feared is that many Haitians in the capital live in tin shacks and are more likely to have survived than those who can afford concrete structures.