TAMPA, Fla, (WFLA) — On Dec. 5, 1945, a squadron of five U.S. Navy Avenger torpedo-bombers took off from the Ft. Lauderdale Naval Air Station in Florida for a routine training mission. Hours later, they would broadcast their final radio call and never be heard from again.

Sunday marks the 76th anniversary of the disappearance of Flight 19 — the infamous “Lost Squadron” that was seemingly lost for the rest of time above the Bermuda Triangle.

According to History.com, the squadron’s routine training mission took off from the Ft. Lauderdale Naval Air Station just after 2 p.m. on Dec. 5, 1945. The planes were supposed to fly east for 120 miles, north for 73 miles, and then back over a final 120-mile leg that would return them to the naval base. But that never happened.

Sometime during their mission, the pilots reportedly experienced trouble with their compasses and lost their flight path. After hours of confused messaging to nearby radio facilities on land, a distorted radio transmission from the squadron’s leader was issued. The leader allegedly called for his men to ditch their aircraft simultaneously as fuel ran desperately low, the website adds.

By that time, radar stations scrambled rescue crews who were unable to find wreckage or remains of the crew due to stormy weather.

Whatever happened to the squadron may never be known, but the story undoubtedly helped sell the legend of the Bermuda Triangle, “an area of the Atlantic Ocean where ships and aircraft are said to disappear without a trace,” the website said.