PHILADELPHIA (CBS) - Electrical wiring has been determined as the cause of a fire that broke out at Jim's Steaks in South Philadelphia, the fire marshal's office announced on Monday. The owner of the iconic Philadelphia steak shop, Ken Silver, assessed the damage from the devastating fire on Monday.

"We'll go through the building, we'll see how devastatingly bad it was because as you can see from the back, the roof is caved in," Silver said.

Eyewitness News cameras tagged along as Silver sifted through the rubble.

"We don't know what we're dealing with yet," Silver said.

He watched as investigators and insurance inspectors shined a light over the damage. They bypassed broken glass, passing by pieces of history with every step.

"I have like so many Bon Jovi pictures. Like I have a whole Bon Jovi file, they just keep coming in and signing," Silver said.

The city fire marshal's office confirmed electrical wiring caused the fire that nearly brought down the South Street staple and everything inside it.

"Old building wires get frayed over time, we're thinking it was something to do with the HVAC system," Silver said.

The fire put 33 employees out of work, some of whom were inside the building when the fire started but were able to get out safely.

The blaze brought soot, smoke and water damage to the Eyez Gallery which is located next door.

"It's a real gut punch, the loss of two iconic businesses is really impactful to our business community and they're really important to South Street," Executive Director of South Street Headhouse Business Improvement District Mike Harris said.

With two iconic establishments now out of commission, it's no secret South Street has been through an unsavory summer.

And it's the South Street spirit Silver says gives them the will to rebuild. In the immediate aftermath of the fire, the owner of Jim's vowed to rebuild the iconic cheesesteak spot. Over the weekend, he reassured fans the building does not need to be demolished.

"When I left here Friday I was devastated and at 12:30/1 Saturday I was like, 'OK, this could be a hell of a lot worse,'" Silver said.

This is what the building looked like immediately after the two-alarm fire on Friday morning. The outside windows are now boarded up so it's tough to tell the extent of the damage inside.

Following the fire, the city's Department of Licenses and Inspections inspected the property and they determined the building is still structurally sound.

Silver says he's cautiously optimistic Jim's will be able to bounce back in the same building.

"Thanks to the great work of Philadelphia firefighters and everyone else that was involved, our building is structurally sound. We were just really starting to hit our stride, you know, then this happens on a Friday morning," Silver said.

Silver says not much of the storage on the third and fourth floors was damaged. He was able to save priceless pictures and memorabilia, including autographed pictures of Kobe Bryant and Tony Bennett.

CBS3's Ross DiMattei and Jasmine Payoute contributed to this report.