Wait until they get to the cars underwater. Most bodies they find will stillbe belted in. I've studied survival in such situatins, and most people panic and cannot escape. The die with their seat belts on, assuming they survive the impact. In any case, it's a sucky situation.
And it’s worse with today’s most-common seatbelt-latch design. It’s DIFFFICULT to unhook with a thin vertical “button” enclosed by the casing from the END of the body.
The old seatbelts were better, where the button was in the middle of the HORIZONTAL plane and easy to push.
Of course, I’m sure they were “thinking of the children” when they re-designed to the vertical orientation - so the children won’t unlatch. Of course.