Overview
- Preliminary findings say the Aug. 11 blast occurred during maintenance to exercise a gas isolation valve in the Battery 13/14 basement, moments after a water flush triggered gas alarms and an evacuation call.
- The valve was cast iron, manufactured in 1953 and refurbished in 2013, and post-incident examination found the body split along a fully circumferential crack, with other recovered valves showing damage.
- Two U.S. Steel employees, Timothy Quinn, 39, and Steven Menefee, 52, were killed, five workers were hospitalized including a Veolia employee escorting a county inspector, and six others were treated for injuries without hospitalization.
- About a month earlier, U.S. Steel identified a cracked, leaking valve in Battery 13, applied a temporary repair, and scheduled replacement of four valves for Aug. 19, with the Aug. 11 work serving as preparation.
- CSB says next steps include accessing internal valve components, metallurgical analysis of cast-iron parts, examination of U.S. Steel’s use of cast iron and valve maintenance policies, and a review of broader safety systems, while the company says the findings align with its own and it is enhancing safety protocols.