The area remains blocked off while federal agents have been called in to look for the cause.
The intersection of 3rd and Market streets is the picture of tranquility today, which is in stark contrast to the scene yesterday when the landmark Suit Corner building was destroyed by fire.
The blaze broke out around 9:00 in the morning and quickly went to two alarms.
The fire department says they were on the scene three minutes after they got the first call and had it under control within 90 minutes, however the fire continued to burn and smolder hours after it began.
At a critical point they shut down the water and let the roofs collapse so they could see inside to zero in on where the hotspots persisted.
ATF agents and the fire marshal are still waiting to get inside the rubble to start looking for the point of origin and the cause.
Federal agents always check out large commercial fires these days.
Steve Bartolomew of the ATF tells Action News, "In this case, the initial estimates were approximately a million dollars in damage and our investigators have to ensure the building and structure are safe to enter before conducting the scene examination."
In the 3rd and Market neighborhood, restaurant owners and merchants are gearing up for what they hope will be a day of back to business as usual. But the presence of ATF investigators continues to dominate the scene.
"We want to determine the point of origin of the fire and its cause, essentially determining where the fire occurred and then how it occurred before we can make a decision, whether it was accidental or intentional," explained Bartolomew.
There are still many detours in the area surrounding the scene and SEPTA bus routes have been detoured in that area. Lower Market Street remains closed, and the fire departments say several blocks of 3rd Street will remain closed all day as the investigation continues.
For the latest on SEPTA's service visit septa.org.