Chemical Accident Closes Busy Chicago Expressway

A truck carrying a dangerous chemical overturned and spilled its load on a busy expressway Wednesday, shutting the route during the morning rush hour and closing several lanes into the evening.

At least 21 firefighters and emergency personnel suffered heat exhaustion while cleaning up the spill on a day when temperatures reached into the 90s. The truck driver was treated for minor injuries.

The southbound truck overturned before 7 a.m. on the Dan Ryan Expressway. Traffic backed up for miles in both directions on the route, also known as Interstate 90-94.

Stranded motorists were told to leave their cars because officials were concerned about the spilled material and a hovering cloud of white vapor. The motorists were later allowed to drive the wrong way off the expressway.

Residents in three nearby high-rises were evacuated briefly, the fire department said.

The cleanup was slowed because the spilled material was flammable. “They’ve had to bring in special tools that don’t produce sparks,” Fire Chief Dennis Gault said.

The truck was carrying azodicarbonamide, a carbon substance used to make foam rubber products, Illinois Department of Transportation spokesman Roy Olson said.

“It’s a very flammable substance, which has a tendency to reignite,” Olson said.

Emergency workers placed mist and foam on the dry chemical to avoid breathing its vapors, Fire Cmdr. Will Knight said.

By 10:30 a.m., the expressway’s northbound lanes were opened. Southbound express lanes were opened by noon, but the local lanes remained closed into the evening.