Authorities confirmed a second fatality after an explosion at the U.S. Steel Clairton Coke Works facility outside of Pittsburgh.

The health department began deploying mobile air units Thursday provided by Pennsylvania’s Department of Environmental Protection and Carnegie Mellon University. The units will travel around Clairton to test for dozens of hazardous air pollutants.

• At least one person is dead, 10 injured and one unaccounted for in an explosion at the Clairton Coke Works in Pittsburgh, Pennsylvania. The cause of the explosion is unknown and officials are investigating, US Steel said.

Regulators are temporarily stepping up pollution monitoring in the Mon Valley after a deadly explosion at U.S. Steel’s Clairton Coke Works on Monday sparked worry about the release of toxic gases. The

U.S. Steel says it believes a gas valve failure led to the explosion Monday morning at its Clairton Coke Works, in which two workers died and 10 others were injured.

A devoted dad has been identified as one of the two steel workers killed from an explosion at a Pennsylvania steel plant on Monday, officials said.

CLAIRTON, Pa. (AP) — Investigators are working to determine the cause of an explosion that rocked a steel plant outside Pittsburgh, leaving two dead and more than 10 others injured, including a person who was rescued from the smoldering rubble after hours of being trapped.

Authorities said their investigation has shifted to the cause of the explosion after they accounted for everyone who was missing.

An explosion at the U.S. Steel Clairton Coke Works about 15 miles southeast of Pittsburgh has left one dead and at least 10 injured, with some people still trapped under the rubble as emergency worker

Family members tell Pittsburgh's Action News 4 Steven Menefee, a father of two, was a loving man who would give you the shirt off his back.