The fire broke out around 10:30 p.m. Saturday on the 1600 block of Bethlehem Pike in Flourtown.
A passerby saw smoke and called 911. Crews believe the fire began inside Flourtown Pizza Restaurant.
"We entered the building within five minutes we had heavy fire in the roof, we evacuated because of deteriorating conditions," said Chief George Wilmot.
Firefighters were able to respond quickly and under tough conditions called in for extra help.
"In this cold weather, it's always an issue," said Chief Wilmot.
The roof of the pizza shop caved in. At two alarms, crews contained the blaze within an hour.
Many of the businesses in the strip mall were heavily damaged, including the pizza shop, which was a total loss.
On Sunday, drivers passed by looking at all the boarded up stores.
"The food is amazing they're fabulous cooks," said Carol Goft.
Goft, a longtime resident, says she's thinking about the family who owns the pizza business.
"They're just really nice people, down to earth, they know all of thier customers," she said.
As for an exact cause, authorities continue to investigate.