The call came at around 11:15 a.m. from Nether Providence Elementary School located at 410 Moore Road in Nether Providence.
Police and fire officials helped evacuate students as the investigation into the leak got underway.
PECO Energy told Action News that a contractor not affiliated with the utility struck a gas service line on school property.
The school's website referred to an ongoing contruction project at the school. It appears the gas line was ruptured as a result that construction work.
PECO crews arrived on the scene and were able to make the area safe by 11:38 a.m. Crews remain on the scene to make permanent repairs.
Meantime, the evacuated students were taken nearby Strath Haven Middle School. School officials said all students were safe and accounted for.
Officials then made the decision to end the school day early. All students were dismissed by noon.