Abstract: On January 2, 2013, Employee #1 and Employee #2 were responding to work orders to an over-heating issue, and an oil leak in boiler #1. Upon arrival they contacted the head custodian at the school about the problems. Employee #1 was repairing the leak and Employee #2 was cleaning up the leaking oil. Employee #1 repaired the leaking flare fitting, and started the procedures to re-fire boiler #1. Employee #2 was also located in front of boiler #1 and began cleaning up the leaking oil. Employee #1 fired the boiler and within seconds an explosion occurred in the breaching and duct of boiler #1 causing a large amount of soot and duct insulation fell on the employees. Employee #1 and #2 were transported to Bayview Medical Center, where they were treated for exposure to soot, dust, gas fumes, vapor mist and smoke to their lungs. The employees remains hospitalized.