The gas leak occurred during maintenance on a boiler, the school is now safe to enter.
On the school's site there is a message states:
PECO Energy Company and the Fire Company have informed us the broken gas pipe at Walnut Street School has been repaired and it is now safe to enter the building. All Walnut Street students will be returned to the Walnut Street Elementary School by 1:45pm and will dismiss from school at the regularly scheduled time.
There were no reports of anyone being harmed at the time of this article.