The move to caskets was also an indication that the mortuary sciences had dramatically improved. Throughout the 18th and 19th centuries, there was a very real and very terrifying chance of premature burial — literally being buried alive, according to Vox. Heightened during the cholera epidemics of the 19th century, scores of people had been declared dead who were actually very much alive. Instead of making sure people weren’t dead before burying them, coffin makers developed the safety coffin, which was rigged with a string (pictured above) that would ring a bell to alert graveyard personnel they needed to be dug out.

A slightly more sophisticated version of the safety coffin was the escape coffin, which had a spring-loaded top that would release with any little movement within the coffin. For those who were buried in vaults, a release valve on the inside became customary, according to Gizmodo. However, the fear of being buried alive isn’t a thing of the past in “coffin times.” In 2010, a patent was granted by the U.S. Patent and Trademark Office for “Apparatus and Method for Generating Post-Burial Audio Communications in a Burial Casket,” per Smithsonian. The system would allow for a device within a casket for communication with the buried as well as wireless programmable audio and music files, while giving “surviving family members the ability to update, revise and edit stored audio files and programming after burial.”