The Cessna made a takeoff from runway 19 at Plattsburgh-Clinton County Airport (PLB) with light wet snow falling, at night. The airplane reached an altitude of 700 feet agl prior to making a steep descent, striking trees and impacting inverted. The accident airplane had come from a hangar and was not de-iced prior to departure. Another Cessna Caravan (N4688B) crashed under the same circumstances just about 40 km (25 miles) away at 21:00 minutes. PROBABLE CAUSE: “Loss of control in-flight after the airplane stalled during climbout. The stall resulted from a loss of lift due to a contaminated wing surface. Contributing to the accident was the failure of the pilot to de-ice the aircraft prior to departure.”