Some cases of “real resurrection” are in fact, cases of live burials, –usually in which the “dead” person wakes up. Depending on whether or not they’re buried in a coffin, the person regaining consciousness may be able to live for long enough to escape. It was a actually a cruel form of execution, more often than an accident, in which the person has time to realize exactly what’s happening to them before they actually die. The “Vesta Virgins” were executed in this fashion, if they broke their vows to the goddess. And numerous saints were martyred by being buried alive as well, according Catholic religious tradition. Even with access to fresh air, if not rescued immediately, there’s still dehydration, starvation, and exposure to consider, as eventual causes of death.
George Washington was so terrified at the prospect of being buried alive, that his last wish was that his relatives waited three days before they buried him. –He was a very superstitious man, but he had reason to be nervous, considering that premature burial has actually happened. Even as late as the 1990’s, hospital patients have been accidentally bagged, and stuck in the morgue while living. With so much fear of accidentally being buried alive, naturally that led to things like “safety coffins”.
Instead of spending money making better doctors, inventors patented devices that would raise the alert if the corpse was actually a man who’d been accidentally buried alive. The device was invented in 1897 by Count Karnice-Karnicki of Belgium, who patented it, –the device was triggered by natural chest movements, and would immediately raise a flag, and release fresh air. However, without a lookout, it was useless. So the undertaker himself, or his employees would sit out in the cemetery all night, and watch for the occasional raised flag, just in case. Hence the term, “graveyard shift”.