There shall be some interesting work done by Divers in the next few weeks I bet. Working in close proximity to the rocks is not going to be much fun. Finding missing parts will be of much interest to the investigators. Determining what damage was caused by the aircraft beating up on the rocks in the surf will have to be part of their effort. I suppose some aerial recce of the cliff side will be in order as well to see if there was any contact with the rocks prior to entering the water.
As the Pilots survived.....they will be able to provide investigators with their best "clues" as to the starting point for figuring this out.