The shop was located on Clark Street near Argyle. Firefighters battled to limit the spread to the adjacent buildings, including a second body shop and an Orange Theory exercise studio, both of which were closed at the time.
"I was sleeping and I heard a muffled explosion," said Chris Randall, a resident. "I sat up and I heard three bigger ones, 'boom, boom, boom,' and fire trucks coming from every direction.
Officials said the extra-alarm fire was first called in around 5:00 a.m. The first companies arrived on scene within three minutes.
The fire likely started in the Smashy Automotive shop and then spread next door to the Star Auto Repair shop, CFD said. The roofs of both buildings collapsed. The products in the shops intensified the fire even more, the fire department said.
The chemicals inside the body shop were an immediate concern to those fighting it.
"The chemicals and type of construction to us is the most dangerous type of fire we can fight fires in," said Chicago Fire Department Chief Thomas Carbonneau. "And so everything was defensive because when fire gets up in the joists, we cannot get at it. That's our biggest fear, obviously, to protect all our men."
When the roof did eventually collapse, both power and gas lines were shut down until the fire was struck.
One person was taken to Weiss Hospital in fair condition after being overcome by smoke inhalation. The cause of the fire is still being investigated.
Fire crews were able to save the Orange Theory Fitness center next door. That business suffered some water damage.
The fire forced organizers to cancel the nearby Waldos Forever Festival.
RELATED: Waldos Forever Fest 2022 cancelled due to morning Clark street fire
A cause of the fire is still under investigations.