Abstract: On July 29, 2003, Employee #1, a facility engineer, was troubleshooting a new gas-fired boiler to determine why it was going into alarm status and shutting down. With the help of a contractor, he removed the boiler's firebox door to determine why the pilot light was not lighting incoming gas. He pushed a button to light the boiler. The primary gas valve had a blocked vent and did not open to allow gas into the chamber. The secondary gas valve opened when its switch failed in the open position allowing gas into the chamber. As they smelled gas, the gas cloud reached the pilot light and ignited, catching Employee #1 in a flareback, burning his face, neck and arms. Employee #1 was hospitalized with second-degree burns.