Abstract: On December 6, 1993, Employees #1 through #4, of the New York City Housing Authority, were repairing an inoperative boiler. After repairing an electrical relay, they attempted to ignite the boiler. Due to an accumulation of soot in the boiler's tubes, the excess gas had not been able to dissipate properly and there was a gas build-up in the vessel. The boiler backfired and its door blew open, injuring Employee #4's right arm. He also received burns to his arm and face. Employee #2 received burns to his cheek and right ear and suffered smoke inhalation. Employees #1 and #3 were also treated for smoke inhalation.