In a statement released Tuesday afternoon, Fire Commissioner Lloyd Ayers said the Fire Marshal determined that the fire started at or near the rear of an auto shop located in the building.
Meantime, one day after the fire erupted members of the Fralinger String Band were on the scene clearing out their props.
It was a Mummer's parade like no other on Wharton Street Tuesday.
Band members were given a few minutes to rush into the burned out garage and grab what they could. They managed to salvage most of their props and floats.
Yesterday, they feared it might be a total loss as flames ripped through the garage they had been using as a prop-building workshop.
It would have been a devastating loss just three weeks before the Mummers parade.
"Members and marshals have been building the props since early October, so trying to fit in two and a half, three months of work into three weeks, that's a tall order for anybody," said Fralinger string band member Dan Marakowski.
The band has a 'haunted' theme for this year's parade. On Tuesday, they felt like they were rising from the dead.
"This is exactly what we were hoping for," said band captain Thomas D'Amore. "Minimal damage. It looks like it's going to be mainly repair work, but that's just a first glance. We'll see when we get a little deeper into it. But feeling very good right now."
A firewall between their garage space and the rest of the building apparently saved the day.
On the other side, the fire spread to an adjacent row house and two others suffered heavy smoke and water damage.
As flare-ups continued throughout the day, fire investigators determined the fire started in electrical wiring inside the wall at the rear of the auto repair shop.
Angel Perez was doing some body work in the shop and says he saw debris starting to fall from the ceiling.
"He was fixing a car, hammering a door when he saw flames coming from the second floor, fell down to the first floor," said Candida Torres, translating for Perez. "And his thing was, let's just vacate the premises because it immediately, in less than minutes, caught on fire."
Perez was renting the space from Joseph Sigismondi who has been cited and fined repeatedly for not having the proper permits.
He was also living in the building with his family, and the building is also not licensed as a rental unit. The investigation here continues.