As irritating as the PA28 single door is, I've never heard of anyone perishing as a direct result of it!
There was an incident involving a PA28 (G-BXRG) a couple of years ago, where the passenger escaped from the ditching but the pilot did not. It is not known what the exact problem was that prevented the pilot leaving the aircraft, but a door on his side might have allowed successful egress.
FBW