The Transportation Safety Board says the Carson Air flight that crashed in the North Shore mountains may have broken up while in flight.
The TSB says the investigation continues but all the evidence points to an in flight break up.
It says the fact the plane dropped 15-hundred meters in elevation in just 20 seconds with no emergency sounded is consistent with a plane breaking up in the air.
The TSB will remove the wrackage next and go over it and all other evidence in the weeks and months ahead in order to deterime an exact cause.
It says with no cockpit or flight recorders the investigation will be a difficult one.