Chicago firefighters battled an extra-alarm blaze at the Quality Truck & Trailer warehouse in the Back of the Yards neighborhood on Saturday.
According to CBS News Chicago, the fire started shortly before 6:30 p.m. in a truck and trailer repair warehouse in the 4100 block of South Oakley Avenue.
By 7:20 p.m., it had been elevated to a 3-11 alarm, which meant at least 12 fire engines, four fire trucks, two tower ladders, and approximately 125 firefighters were responding to the fire.
A Level 1 hazardous materials response also was initiated after neighbors said they heard explosions from the warehouse before firefighters arrived.
According to unconfirmed fire dispatch reports, there were, indeed, explosions inside the building after the fire started.