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

A deadly explosion at an industrial plant outside Pittsburgh on Monday morning left two people dead and many others injured.

The mill, which is part of the recent merger between U.S. Steel and Nippon Steel, has faced scrutiny from federal and local ...

An explosion at a U.S. Steel plant near Pittsburgh left one person dead and sent at least 10 to hospitals and heavily damaged ...