CHICAGO (WLS) --A fire at a large West Humboldt Park flea market continued to smolder three days later.
"This is a significant fire. It's going to take a while for this to be investigated thoroughly," said Tom Ahern.
The Chicago Fire Department announced it has asked for help because of the scale of the investigation. So now the Bureau of Alcohol, Tobacco, and Firearms national response team will collaborate with police and fire to help figure out the cause and origin of the Buyers Flea Market.
"Our office of fire investigations has limited resources and the sheer size of 300 by 600-foot building surpasses the manpower of the Chicago Fire Department has to work the scene," said Richard C. Ford II, first deputy fire commissioner, Chicago Fire Department.
On Tuesday morning, hundreds of cars were swallowed up in flames, and hundreds of businesses, which sold things like jewelry, furniture and food every Saturday and Sunday, were destroyed. The flea market has been in the community for 30 years.
"This is a fire of enormous scope," said Chief Gene Roy, Chicago Police Department.
According to fire officials, the probe will require significant amounts of debris, lost merchandise and more than 100 vehicles to be moved from the collapsed structure.
The ATF has set up a mobile lab staffed by an elite group of experts. Officials say special canine teams will also be used. They plan to shore up the building first and the investigation could take weeks.
"You gotta make sure the building doesn't fall on anybody," said Jeffery Macgee, ATF special agent in charge.
The ATF routinely helps the fire department with fires in commercial structures, but this is the first time the national response team has responded to an event in Chicago, according to CFD.
Investigators say they are not ruling any cause out.
Vendors were invited to participate in the Maxwell Street Market instead, but some said that's not possible.
"We saw the invitation," said vendor Alicia Gregorio. "We have nothing... we don't have money to invest."