Heckle was a member of Boy Scout Troop 101 in Linn County, Iowa 1973. The group camped at the Kiwanis Cabins along the Cedar River between Palo, Iowa and Toddville, Iowa on February 3, 1973. The area was near the Duane Arnold Energy Center.

Heckle was last seen at approximately 8:00 p.m. He was playing a game of "Capture The Flag" with other members of his troop at the time of his disappearance. Heckle has never been heard from again. He was not missed until bed-check that evening. The Scouts attempted to locate him for 90 minutes before summoning authorities to the scene. Volunteers searched the reserve near the river's ice-clogged backwaters for evidence. Heckle's quilted nylon parka was found snagged on to a log along the Cedar River's east bank. The jacket was still zipped at the bottom. No other sign of him was uncovered. The weather was mild at the time he disappeared, but shortly afterwards there was a snowstorm in the area.

There is no indication of foul play in Heckle's disappearance. Investigators generally believe he slipped into the river and drowned, but they admit it is possible that something else caused his disappearance. He was a fifth-grader at Eisenhower Elementary School in 1971, and was considered a good student in 1973. He resided with his parents in the 1500 block of 48th street northeast Cedar Rapids, Iowa. Heckle's case remains unsolved.