The purpose of the flt was to transport 3 student parachute jumpers. After the jumpers egressed, the plt & jumpmaster returned to the arpt. During the landing, the acft hit a ridge on the grass rwy & bounced in the air. The acft then touched down in a crab, slid sideways & the left main gear collapsed. According to the plt, the wind was from the northeast at 5 gusting 10 kts.