At 11:15 PDT, a Bell 206-L4 piloted by actor Harrison Ford landed hard and rolled over in the Lake Piru riverbed near Santa Clarita. The helicopter was substantially damaged but the two occupants were uninjured. The flight instructor reported that he and the trainee were practicing autorotations to a power recovery in the dry riverbed. On the second attempt, the trainee flared about 150 to 200 feet agl and attempted to bring in power to initiate the power recovery, but the power did not come back in time to recover to a hovering position. The helicopter landed hard and slid forward in the loose sand. The left skid struck a log and the helicopter rolled over onto its left side. No pre-accident anomalies were found.