This is a serious article. No, really.
"But, in reality, you can’t protect a corpse from itself. While you’re insulating grandma from the outside air, she could be stewing in her own fluids, turning into a slurry from the work of anaerobic bacteria. When the weather turns warm, in some cases, that sealed casket becomes a pressure cooker and bursts from accumulated gases and fluids of the decomposing body. The next time relatives visit grandma, they could find her rotting remains oozing from her tomb in the form of a nauseating thick fluid."
Bryan McEntegart, Roman Catholic Archbishop of Brooklyn, was buried in a crypt in Huntington, Long Island, in 1968. His casket exploded one day and blew the front of the vault all over the crypt.
When Henry VIII of England was being transported to Windsor Castle for burial, his casket lay overnight at Syon Monastery in west London. His casket also exploded, allegedly fulfilling a prophecy made some 12 years earlier by a disaffected monk. Dogs ate a portion of the remains.