There are no good ways to go, but burn victim may be the worst.
A friend and his brother go to open up the fishing cottage, the older brother goes in and flips a light switch, propane leak, massive burns.
From the hospital bed, he begs the younger brother to go home, use a hacksaw cut off the barrel and stock of a shotgun.
Bring it and a cartridge.
He has to kill himself to escape the pain.
He survived after years or repair work.