A legend exists about the first nuclear "pile" constructed in 1942 beneath the football bleachers at the University of Chicago. In addition to both crude, built-in, and jerry-rigged safety mechanisms for preventing a runaway nuclear reaction or, worse, an explosion, a single safety rod was suspended above the pile by a rope, which was tied near the operator's panel. Alongside the rope was a readily available hatchet, to cut the rope and drop the shut-off rod.