Back in the "good old days," people used to harbor a very real fear that they might be declared dead and put in the ground while still alive. According to CDs by Bob Hiebert, an authority on the topic, in the 19th century numerous patents were given in England and the U.S. for devices by which the elect could decline the nomination, either by signaling to people on the outside (bells, flags, electric lights activated from inside the coffin) or escaping on their own. One very common device for such matters was a bell mounted on the coffin lid, with a string running down inside the coffin, which the corpse could pull to call for room service. A bell like this figures at one point in Nicholas Meyer's book "The Great Train Robbery." In this novel, Meyer tells us that macabre 18th century tales about exhumed corpses that had been found to have clawed at the interior of the casket were not wholly fanciful: graveyard excavations reveal that nearly two percent of those interred before the advent of embalming in the 20th century were buried alive. One possible explanation for the clawed-casket stories was post-death contractions of the muscles of the deceased occurring inside the casket after burial. But according to "the Doc" (Mr. Hiebert), this logic makes little sense: rigor mortis sets in a few hours after death and locks the muscles in whatever position they are in at that time; the muscles relax 12-24 hrs after that, when the first stage of decomposition softens them to the point that they cannot hold the bones in place, and of course they cannot move or contract again at this point. Therefore, these stories of people being buried alive must be true.