Well...they found him, in the yard, with the water heater and a hole in the roof of his barn. Air compressor running inside the barn, with some unconnected piping leading to it.
As best anyone ever figured (no witnesses), he was rigging the water heater tank as a reserve air tank for his compressor, which is a bad idea to begin with. But for some inexplicable reason, after he had hooked up the tank to the compressor, and pressurized the tank, he had to climb on top of the tank to do something (bolt it to the wall, adjust a valve, sweat a pipe, I have no idea). It was at that time the bottom of the tank chose to blow out, launching itself, and him on top of it, through the roof into the yard.
My family's full of stories like this (though this is the only fatal one - my dad sending his brother's boat over Niagara Falls, after his brother was shipped to 'Nam and told him "Take care of my boat" was close, but Dad lived. Likewise, when my dad called me and asked "Any ideas how to get a riding lawn mower out of the pool?")
We. Are. Farmers. Dum, dum-dum dum dum dum dum.