According to the pilot, he was landing on runway 15 when the airplane encountered wake vortices from an aircraft which had just departed runway 33. At 50 feet above ground level, the airplane rolled hard to the left and the stall warning horn activated. The pilot added power and the airplane rolled hard to the right. The pilot was able to stop the roll; however, the nose dropped and the right main landing gear impacted the runway, resulting in substantial damage. The pilot did not report any anomalies with the airframe, flight controls, engines, or weather.