The fire broke out around 5:15 a.m. Sunday at the now vacant Concord Chemical Plant on the 1700 block of Federal Street in Camden.
Shortly after firefighters received reports of smoke coming from the building, flames began shooting from the upper floors.
"My brother is like 'we gotta leave now, the soap factory is on fire,'" neighbor Dennis Gonzalez said.
"They told us we have to evacuate very quickly, the smoke was very harmful for us and we needed to get out of the area," neighbor Brian Wooten said.
No injuries have been reported, but parts of the building collapsed and area homes had to be evacuated.
Local fire companies battled the blaze for more than three hours before it was under control.
Hazmat crews were called, with the concern of possible chemicals still being inside the building. However, the former soap making facility underwent a $1 million EPA clean up in May, when many of the hazardous chemicals were removed.
"Everything that was volatile and very toxic was removed. Anything that was miniscule that they didn't consider a hazard to us or anybody else was left in the building," Camden Fire Chief Michael Harper said.
This is the fourth major fire in two weeks in Camden.
This string of Camden fires started 10 days ago on June 9th with a 12-alarm inferno at a former tire factory at Chestnut and Orchard streets. 13 homes were destroyed and 55 people were left homeless.
Two days later, an 8-alarmer at an abandoned factory on the 400 block of Winslow Court displaced 19 families.
This past Monday, a 1-alarm blaze broke out at an old furniture store on Marlton Pike.
ATF investigators along with the Camden County Prosecutor are now handling the investigation into this latest blaze.
Arson appears to be the cause, but how the fire started has not been determined.
Investigators are hoping residents will come forward to report anything suspicious in the early morning hours.
The fire department says the building and others like it in the city have been inspected, but break-ins continue to be a problem.
The prosecutor's office tells Action News no one is in custody, but detectives towed away a vehicle found near the building and are processing it to determine if it had a role in the blaze.