"An unexploded 4″ firework shell from the fireworks display.

My dad put a fuse in it and lit it off in the church parking lot across the street for New Years.

Those are NOT supposed to go off on the ground. It sent fireballs 300 feet in all directions. (Except down, of course.)

(Edit) Dad turned 83 in June. Somehow he still has all his appendages, both eyes, and most of his hearing."