Stabbed through the heart by a lightsaber, falls off a bridge suspended high above the ground, immediate area explodes shortly after.
He's still alive.
Noi he's not alive, the whole point about his death are that it mirrows Vader's killing of Kenobi.
Couple these with the fact that Ford wanted his character to die in the OT and didn't want to come back for the new films in the first place and you've got a pretty obvious answer.
To be fair, Darth Maul survived being cut in half and falling down a reactor shaft.