Mary Elizabeth Dietz went missing on October 14, 1997, at 3:30 a.m. She was last seen at her residence on Lantern Lane in Selbyville, Delaware, waiting for the morning newspaper. Her son reported her missing. Foul play is not suspected in her disappearance.

Dietz was often seen in a disoriented state and was known to dig through a dumpster behind her home. On the day of her disappearance, a trash collector saw the dumpster empty, with the door open at the side. Authorities believe that she may have accidentally been taken to a landfill after getting stuck in the dumpster. They searched the landfill but found no trace of her. Her case remains unsolved.