Allard was visiting family members in Miami, Florida when he disappeared on August 30, 1976. He called his mother and asked permission to return to their home in Connecticut, and she sent an uncle to pick him up. By the time his uncle arrived to meet him, however, Allard had vanished. He was last seen walking on Bird Road near 112th Avenue in Miami, headed for a 7-11 store. He never actually arrived at the store, however.

Investigators believe Allard may have initially tried to go back to his home in Connecticut, but he never made it there and has never been heard from again. His family believes he may have been abducted while attempting to hitchhike to Connecticut. Few details are available in Allard's case. The original investigative casefile was lost and authorities have opened another decades after his disappearance. Both Florida and Connecticut police are investigating his case.

Some agencies give the date of Allard's disappearance as August 13, 1976.