WW2 ordnance is found from time to time. The most bizarre instance that I know of was the sinking of the fishing trawler Snoopy in 1964 when it dredged up an old German torpedo while fishing off the coast of North Carolina. The torpedo exploded when it was brought to the surface killing 8 fisherman and sinking the ship. The last casualties of WW2 that I’m aware of.
Lt. Hiroo Onoda and his comrades were causing trouble (including a few fatalities) on a Philippine island as late as 1972, when the last of them (Onoda excepted) was killed by police.