1400 feet per minute is a VERY high sink rate that close to the runway for any airplane. I question how that information was obtained. But assuming it is correct, why did that happen? Only two possibilities short of intentional pilot nefariousness: stall or microburst. I suppose the pilot could have been exhausted and allowed the plane to get too slow and stall. Or an unexpected microburst could have cropped up and forced the plane to descend too fast and hit the seawall. In either case, that anyone survived is pretty miraculous...
Yeah. My fourth or fifth though was microburst.