WEST CHESTER, Pa. (CBS) — Residents in West Chester are allowed to return home after being asked to evacuate following an electrical fire that injured 12 firefighters.

The West Chester Fire Department ordered residents and businesses within the 100 and 200 blocks of West Gay and Market Streets to evacuate the area early Wednesday evening over the threat of carbon monoxide exposure. That order was lifted about four hours later.

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The fire department said it would be going door-to-door to check for carbon monoxide levels within homes and buildings.

“Somebody walking by smelled smoke, so that’s the way the initial call was dispatched,” said Chief Mike McDonald, with the West Chester Fire Department

Twelve West Chester firefighters had to be evaluated for carbon monoxide exposure after battling the underground fire at 200 Gay Street at the Old West Chester Courthouse.

Five of them were transported to the hospital. The other firefighters were evaluated at the scene. Their injuries were not believed to be severe in nature.

“You could see smoke coming up from the sewer,” said Stephanie Hallowell.

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Hallowell works at a nearby restaurant and watched as firefighters rescued one of their own who collapsed.

“He sat up eventually and he seemed to be ok and a few minutes later they came back to the restaurant asking for more help,” said Hallowell.

Assistant Fire Chief Mark Scanlon briefly lost consciousness but was quickly revived by colleagues. He was rushed to Chester County hospital where he’ll spend the night.

“He doesn’t want to be there. He thinks he’s ok. We think different and he’s going through treatment for CO poisoning,” McDonald said.

PECO crews were on the scene as nearly 80 customers were without services due to an underground equipment issue.

Authorities are going to continue to watch the area where this began, just in case there’s another flare-up. They expect to have all firefighters home from the hospital soon.

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