Clairton, Aug. 12 -- An explosion on Monday at a US Steel coking plant near Pittsburgh has left people trapped under the rubble, with emergency workers on site trying to rescue them, an official said. There are no confirmed fatalities yet at the Clairton Coke Works, said Abigail Gardner, director of communications for Allegheny County. The Allegheny County Emergency Services said a fire at the plant started around 10:51 am (local time) and that it has transported five people. The agency did not provide any more details on those people transported and would only say it was an "active scene". The plant, a massive industrial facility along the Monongahela River south of Pittsburgh, is considered the largest coking operation in North America and is one of four major US Steel plants in Pennsylvania that employ several thousand workers. Democratic Sen. John Fetterman, who formerly served as the mayor of nearby Braddock, called the explosion "absolutely tragic" and vowed to support steelworkers in the aftermath. "I grieve for these families," Fetterman said. "I stand with the steelworkers." AP...