The foreign-registered airplane was substantially damaged at about 1015 Eastern time during impact with trees and a house shortly after takeoff. The commercial pilot and one passenger were seriously injured; another passenger sustained minor injuries. Visual conditions prevailed. The flights purpose was to ferry toys and relief supplies to Haiti. The pilot stated he retracted the wing flaps “too early” after takeoff. The airplane impacted a tree and the pilot shut down the engine prior to impacting a house approximately one-quarter mile from the end of the runway.