An inspection contractor found a chemical tank at a Washington state paper mill “not fit for continued service” 10 months before it failed in May, killing 11 in one of the deadliest U.S. workplace disasters in recent decades, according to a federal report released Friday.

An inspection contractor found a chemical tank at a Washington state paper mill was unfit for service 10 months before its fatal failure in May. The U.S.

An inspection contractor found a chemical tank at a Washington state paper mill was unfit for service 10 months before its fatal failure in May