6 years ago. High volume NYC tour operator conducting "doors off, feet out" tours where pax sat on cabin floor, feet hanging out, restrained with a simple nylon harness. AS350. On this fateful flight, one of the passenger harness attachment assemblies got wrapped around the engine control lever, bringing the lever to the shut-off position initiating an engine failure. I believe the pilot was the only one who got out alive as the five passengers were restrained to the helicopter. Poorly briefed pax. No quick release.  Also relatively inexperienced and low paid pilot. Tragic all around.