The leak happened at 9:25 a.m. on the Spring Mill Ave, near the 200 block of East 4th Street.
According to PECO, the building that was affected was a large home that was subdivided into 10 apartments.
The incident happened after a contractor hit a gas service pipe to a building that caused as strong gas odor.
Residents in those 10 apartments were evacuated while PECO contained the leak.
They were allowed back inside at 10:00 a.m.
