PHILADELPHIA, July 5 -- For 145 years, whatever else went wrong at PECO, the linemen always showed up. That streak ended at 12:01 a.m. Saturday, at the exact moment a heat wave was pushing the region's power grid toward its limits.

Roughly 1,600 members of International Brotherhood of Electrical Workers Local 614, linemen, gas odor responders, technicians, call center staff and back-office workers who keep PECO running for 1.7 million electric customers and 550,000 natural gas customers across Philadelphia and its suburbs, walked off the job after more than five months of negotiations failed to produce a contract, the Philadelphia Inquirer reported. It is the first strike in the utility's history. The union has been working without an ag...