Report: Bolt missing in crashed Vegas tour copter

Investigators who combed the wreckage of a fatal Las Vegas sightseeing helicopter crash in December say some critical steering hardware was disconnected, and the tiny parts that should have secured it weren't found on the scene.

The finding was among documents released Friday by National Transportation Safety Board officials in the Dec. 7 crash that killed a pilot and four tourists.

Investigators say a rod wasn't connected to the fore/aft servo, which adjusts the position of the main rotor blade to control the aircraft's lateral direction.

A failure there could explain the helicopter's erratic climb, turn and dive before the crash.

Records show the mechanism was overhauled the day before but passed inspections on crash day.

The victims' lawyer says he suspects a tiny bolt came loose and caused the failure.