NTSB will be able to determine the altitude of the drop by the damage. Estimating altitude over water at night is dangerous, I don't fly but as a paratrooper we lost men who got out of their harnesses too soon and dropped hundreds of feet to their deaths - if there were not working altimeters or faulty ones they may have got surprised and thought they were in imminent impact with the sea and did a hard nose up creating a deep stall. Just throwing this out. Fit facts?