Investigators have found nothing wrong with the engine of the helicopter that crashed into New York City's East River, killing five passengers.
The National Transportation Safety Board said Thursday it found "no evidence of abnormalities" during a teardown of the engine. It also said its investigators interviewed the chopper's pilot for the first time.
The five passengers drowned when the helicopter touched down in the river on Sunday and capsized. The pilot survived.
The NTSB says it's examining whether the passengers' safety harnesses hindered their escape from the sinking aircraft.
The family of one of the victims has filed a lawsuit against the aircraft's owner, Liberty Helicopters, calling the passenger harness system a "death trap" in a water crash.
Liberty Helicopters has referred all inquiries to federal officials.