On May 13, 1999, at 1005 central daylight time, an Air Tractor AT-400, N36493, collided with trees shortly after takeoff, in Louisville, Mississippi. The airplane was operated by the commercial pilot under the provisions of Title 14 CFR Part 137, and visual flight rules. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight. The pilot was not injured and the airplane sustained substantial damage. The flight departed Louisville, Mississippi, at 1000. The pilot reported that about three or four minutes after departure, he heard a loud whining and grinding noise from the engine compartment for several seconds. The pilot then heard an abrupt loud noise that resulted in a total loss of engine power. The pilot stated that he looked at the torque gauge as the needle fell to zero, he then traded airspeed for altitude gain and applied full flaps, setting up the aircraft for an emergency landing into the trees. The examination of both the fuel line and engine was conducted. The fuel line examination detected that there was no fuel in the fuel line or at the fuel controller, and very little in both main tanks. The engine examination concluded that less than 1 oz. of fuel was found in the engine fuel filter, and less than 12 oz. of fuel was found in the firewall fuel filter. Less than a gallon of fuel was recovered from the fuel system. No fuel spillage noted at the accident site. The examination of the engine assembly failed to disclose an obvious internal component malfunction or failure.