The version I was led to believe....
On the first diversion demand, the pilots changed heading but on approach discovered they couldn't land there.
When the second diversion destination was demanded by the hijackers, the pilots pointed out they didnt have enough fuel to get there, the hijackers forced them to continue, and eventually the aircraft went in to ditch.
The Hijackers were convinced by now that the pilots were trying to trick them and one grabbed the controls as the aircraft was imminently ditching, just feet above the water. As a result, one wingtip hit the water first and was torn off, sending the aircraft into the water at a catastrophic angle.
Experts say ifit hadnt been caused to list, it looked like it would have been a succesful ditching.