Sheriffs telling pedestrians to get off West Gay Street ... PECO says they shut off power to 79 customers due to underground fire @6abc pic.twitter.com/iLBP0mk51N — Annie McCormick (@6abcAnnie) August 9, 2017

EMBED >More News Videos 12 firefighters injured in underground West Chester fire. Annie McCormick reports during Action News at 6 p.m. on August 9, 2017.

EMBED >More News Videos 12 firefighters injured in West Chester. Brian Taff and Sharrie Williams report during Action News at 4 p.m. on August 9, 2017.

WEST CHESTER, Pa. (WPVI) -- High carbon monoxide levels and an underground fire led to evacuations in downtown West Chester and sent five firefighters to the hospital.The call of smoke came in shortly before 4 p.m. Wednesday on the 200 block of West Gay Street, near the Justice Center.Firefighters found a smoldering cable underground and, separately, they responded to a small fire in a house nearby."Once we started getting more crews and started checking the residences, we realized it was more than a little more than just underground PECO wires burning and a little fire in a house. We were actually getting high CO readings on the street above the manholes," West Chester Fire Department Chief Mike McDonald said.Carbon Monoxide became the main threat. Crews evacuated a handful of residents and some businesses."As the stuff was burning, it was pushing the gases into the residences and up to the manholes, that's where the CO came from," McDonald said.Assistant Fire Chief Mark Scanlon was overcome by fumes."There was a firefighter laying on the ground; they brought in a gurney and they were working on him," resident Maria Ruffin said.Ruffin took photos as Scanlon's fellow firefighters worked to revive him."When he came outside the building, he collapsed, and he was unresponsive, momentarily. Once he got out into the fresh air, once the guys started reviving him, he came around," McDonald said.Four other firefighters were also transported to the hospital.PECO responded and immediately began repairs on the underground cables, restoring most of the power several hours later.----------