Aug 11 (Reuters) - An explosion at a U.S. Steel plant

near Pittsburgh on Monday has killed one person and injured

multiple others, with at least two people missing, police said,

as fire crews could be seen battling flames while heavy smoke

rose from the facility.

The explosion occurred at about 11 a.m. at the U.S.

Clairton Coke Works plant, which is owned by U.S. Steel, a

subsidiary of Nippon Steel ( NISTF ).

Allegheny County Police spokesman Jim Madalinsky said at

least two people were missing, as well as reporting the one

fatality and multiple injuries.

The extent of the injuries was not known, but news

accounts said that several people were taken to hospital burn

units.

There was no word yet on a possible cause of the

explosion.

Clairton Mayor Rich Lattanzi in a phone interview with

Reuters from the site described the scene.

"I don't know if people are trapped," Lattanzi said.

"There are ambulances and police and news media everywhere. It's

a horrible day for Clairton. We're praying for everyone

involved. We're just praying this isn't as bad as it looks."

Pennsylvania Governor Josh Shapiro posted on X that his

administration was in touch with local officials in Clairton as

they responded to the explosion.

"The scene is still active, and folks nearby should follow

the direction of local authorities," he wrote, asking readers to

join him in prayer for the Clairton community.

An official told CNN that some people were trapped under the

rubble, and emergency crews were working to reach them.

The Clairton Coke Works, located on the Monongahela

River south of Pittsburgh, is the largest coke manufacturing

facility in the United States. Coke is produced by heating coal

at high temperatures. It is used in blast furnaces as part of

the process of making steel.

Clairton Plant operates 10 coke oven batteries and

produces approximately 4.3 million tons of coke annually. The

facility serves customers in the commercial coke market as well

as U. S. Steel's steelmaking facilities.

In June, Nippon Steel ( NISTF ), Japan's biggest steelmaker,

closed its $14.9 billion acquisition of U.S. Steel after an

18-month struggle to obtain U.S. government approval for the

deal, which faced scrutiny due to national security concerns.