Authorities have identified the second person killed Monday in an explosion at U.S. Steel’s Clairton Coke Works.

Steven Menefee, 52, was pronounced dead at 7:26 p.m. at the scene of the blast, the Allegheny County Medical Examiner’s Office said Thursday. He lived in the Westmoreland County community of Tarrs.

The explosion at the nation’s largest coke manufacturing facility, also killed Timothy Quinn, 39, of South Huntingdon, and injured 10 others.

The blast occurred around 10:47 a.m. Monday, spewing a huge black cloud into the air and triggering an hourslong rescue and recovery effort to pull people from the site of the explosion.

Officials have not provided any explanation for what may have caused the disaster, but multiple agencies are investigating.

There were no indications of safety concerns leading up to the blast, according to Scott Buckiso, senior vice president and chief manufacturing officer of U.S. Steel’s North American Flat-Rolled segment.

Much of the plant, which lies 20 miles south of Pittsburgh in Clairton, was operational by Tuesday. U.S. Steel CEO David Burritt told reporters during a Tuesday press conference that there was no risk in continuing operations at the site.

Ten others were injured in the explosion, including an county Health Department employee who was treated at a hospital and released.

County health officials have said air and water quality tests showed levels within federal limits during and after the explosion.

Nearly 1,300 people work at the Clairton plant, according to U.S. Steel.

The Clairton facility is part of U.S. Steel’s Mon Valley Works, an integrated steelmaking operation that also includes the Edgar Thomson Plant in Braddock, the Irvin Plant in West Mifflin and a finishing facility called Fairless that is situated near Philadelphia.

The Clairton plant produces about 4.3 million tons of coke annually.

Before Monday’s explosion, the most recent accident at the site was in February, when a hydraulic issue caused an explosion that injured two people. A worker was killed in an explosion at the site in 2009.