The NTSB is asking for help in its investigation into a deadly helicopter crash in the Grand Canyon. Air Safety Inspector Stephen Stein says investigators want to talk with anyone who may have seen the Papillon Airways chopper before it went down over the past weekend.
Three British tourists were killed in the accident and four others were injured.
Investigators are taking a good look at the wreckage of the aircraft. Stein says specific components of the helicopter will be examined, along with archived radar data and pilot certification.