A 2011 Nevada helicopter crash that killed the pilot and his five sightseeing passengers was caused by poor maintenance, according to an investigation by the National Transportation Safety Board (NTSB). Also contributing to the accident: degraded material, improper installation, and inadequate inspections.

The National Transportation Safety Board (NTSB) has released preliminary information about it's investigation into the deadly crash of a private helicopter in New York's East River Oct. 4th. One passenger was killed and two sustained serious injuries in the accident.