A pilot's rendition of the crash (11 second vid related)
Heli is on a pre-planned straight path. Plane turns to land on runway 33 as instructed. If this is how the crash happened, I put most of the blame on ATC for not warning the heli in time. Heli didn't have time to turn left and fly behind the plane. One pilot's explanation at the link below.
https://news.yahoo.com/news/pilot-view-why-helicopter-did-153659445.html