The aerial photo flight was commencing with the pilot and operator on board. A witness reported that the engines sounded good on the ground and during the takeoff ground roll. At about 30 to 40 feet above ground level, he heard 'surging' sounds from the airplane. He then observed the aircraft in a shallow right hand turn as it approached departure end trees. He then saw the aircraft roll off to the left, into the trees in a steep, nose low, left wing low attitude. The aircraft crashed into trees and terrain and was destroyed by impact forces and fire. Investigation revealed that the aircraft impacted the ground in a left wing low attitude. The main wreckage was found inverted. An inspection of the engines did not reveal evidence of a mechanical failure or malfunction. Examination of both turbochargers revealed evidence of rotation at impact. Examination of both propellers revealed evidence of blade tip twisting toward low pitch and some forward bending.