Abstract: At 9:30 a.m. on October 15, 2021, three employees were working near a steam boiler located at a hazardous waste collection facility. Employees #1 and #2 were employed with Clean Harbors Environmental, and Employee #3 worked for Vicinity Energy, LLC who owned the facility. The employees were working near an auxiliary steam system that feeds the boiler automizing steam to the burners and fuel oil heaters when a 6 in by 4 inch fitting failed on an auxiliary steam line operating at a nominal 200 psi. The cast iron tee fitting failure resulted in an explosion and release of high-pressure steam directly into the operating floor outside the control room. The steam release was accompanied by a loud high-pitched noise. Employees #1 and #2 received burned and scalding to the arms and back form the steam release, and Employee #3 suffered a concussion from the explosion. All three employees required hospitalization. Vicinity Energy, LLC did not have a steam trap maintenance program to ensure the proper operation of traps that drain off condensation to prevent damage to system parts and components.