Live burial
Live burial or premature burial is interred in a grave while still alive. Some cases of premature burial occurred because the technology to accurately determine death didn't exist so people were routinely wrongfully pronounced dead when in a coma or similar vegetative state. To guard against this, some cultures buried the dead with bells that could be rung if the person in the coffin was still alive, so they could be rescued. Live burial has also been used as a form of murder or execution. A related practice is immurement.