The National Transportation Safety Board released their preliminary report on what led up to that fatal helicopter crash on Kaua'i in December, killing all seven people on board. 

According to the report, a witness heard the high-pitched noise coming from the helicopter, which seemed to be hovering above a hiking trail in Koke'e State Park. The witness said weather conditions were also rainy and foggy at the time of the crash.

Authorities in the report are calling the incident an "accident," indicating the aircraft hit mountainous terrain, at a location over 3-thousand feet above sea level.