The Federal Aviation Administration said Friday that a tarp caused damage to a helicopter’s rotor blades after landing on Kauai’s remote Kalalau Beach Wednesday.

The pilot was uninjured, but the two passengers who were state Department of Land and Natural Resources employees, sustained minor injuries, Airborne Aviation’s co-owner said.

The Hughes 369 helicopter, tail number N519PA, had landed at about 1:45 p.m. when a tarp on the ground blew into the rotor blades, damaging the aircraft, the FAA said.

The National Transportation Safety Bureau and the FAA are investigating the incident.