Looking at a topo map, this island has higher elevations of up to 464 feet . . . I'd be hard pressed to believe the whole thing is gone, unless something much bigger than a hurricane hit it . . . devastated is believable, but gone just seems far fetched . . . unless swallowed by the earthquake . . .
Maybe those flying over just don't recognize the island anymore. It is just fragments of its former size and shape? I don't know the record number of deaths from a hurricane, but I think it was no more than 8,000 or 9,000. More deaths for typhoons, but this could be a record for the Atlantic, if true.
Pilot error?
That would have to be a giant tsunami, or the island would have had to have been swallowed up by the quake, as you said.