Details of Disappearance Day disappeared from National City, Illinois on August 10, 1990. Her remains were found in a secluded area of Pike County, Missouri only sixteen days after she disappeared, but she went unidentified for 26 years. Police boiled the corpse's bones, a common practice at the time that was meant to preserve them. However, boiling destroyed the soft tissue and therefore the DNA.
In July 2016, police discovered an overlooked thumbprint from the Pike County body and were able to match it to Day. Her case is being investigated as a homicide.