Listed on cracked.com as the fifth Creepiest Urban Legends (That Happen's to be True) is the phenomenon of being "Buried Alive"!!
The Legend (to quote the website):
"Some poor schmuck is committed to his or her eternal resting place, even though they aren’t quite ready to take that final dirt nap. Scratch marks are later found on the coffin lid along with other desperate signs of escape."
"This not only happened, but back in the day it happened with alarming regularity. In the late 19th century, William Tebb tried to compile all the instances of premature burial from medical sources of the day. He managed to collect 219 cases of near-premature burial, 149 cases of actual premature burial and a dozen cases where dissection or embalming had begun on a not-yet-deceased body."
"The concern over being buried alive back then was so real that the must-have hot-ticket item for the wealthy and paranoid were "safety coffins" that allowed those inside to signal to the outside world (usually by ringing a bell or raising some type of flag) should they awake 6-feet under. Though, answering that bell sounds like a good way to get ambushed by a zombie if you ask us."
Nathan Birch on cracked.com