A witness to the deadly crash of a helicopter carrying Kobe Bryant and eight others said it sounded normal just before slamming into a hillside and wreckage examined by experts  at the scene showed no sign of engine failure, federal investigators said in a report released Friday.

The helicopter carrying Kobe Bryant and eight others that crashed into a rugged hillside outside Los Angeles was flying in foggy conditions considered dangerous enough that local police agencies grounded their choppers.