Cause of Philadelphia fire sounds alarm over aging U.S. refineries

PHILADELPHIA (Reuters) - How did a piece of piping installed when Richard Nixon was U.S. president go without once being checked before leading to a fire that devastated the East Coast's largest and oldest oil refinery? That's a question safety experts and activists are putting to regulators after the devastating fire at the Philadelphia Energy Solutions (PES) refinery in June, worried more disasters are waiting to happen in an industry reliant on old equipment.Last year, U.S. refiners processed..