Flames broke out at the Wawa on the 300 block of Main Street in Harleysville around 2 a.m. It took firefighters nearly 2 hours to put the 2-alarm blaze under control.
Investigators say the fire started behind the building near two electrical boxes. It quickly spread to the inside of the store.
PECO crews cut power to the building so firefighters could use more water to fight the fire.