The flight instructor reported that during final approach the airplane drifted off the left side of the runway after encountering a wind gust. He told the student pilot to initiate a go-around. As the student pilot increased engine power for the go-around the airplane pitched-up and then rolled to the left. The flight instructor assumed flight control of the airplane, but the airplane impacted left-wing low off the left side of the runway. The airplane cartwheeled and both wings separated from the airplane. The local area winds were out of the north-northwest at 10 knots, gusting 17 knots. The flight instructor reported that the local topography produced a "strong wind current" that contributed to the accident.