Four of seven passengers were killed Thursday morning when the Ford Explorer they were riding in veered off the Eisenhower Expressway in Addison and rolled over several times before landing in a ditch, authorities said.
The driver of the vehicle, Margot Santillan, 31, of Chicago, was charged with improper lane use, failure to reduce speed, driving without a valid license and driving without insurance, police said. She also was cited for driving on a suspended registration.
The accident happened about 6 a.m. on westbound I-290, roughly a mile west of Route 83. Four women were pronounced dead at the scene while four survivors -- Santillan and three men -- were taken to area hospitals.
Illinois State Police Lt. Brian Windle said the investigation is ongoing but it appears "speed and a lack of seat-belt use" contributed to the fatalities. He said police were trying to confirm the victims' identities.
"Our condolences go out to the families," he said at a news conference in Addison.
Police said all of the victims were from Chicago. The deceased ranged in age from 28 to 44. The survivors are between 28 and 51 years old.
The crash was reported in a 911 call, but police said no one stopped to help or give information. They were trying to track down eyewitnesses but as of Thursday afternoon had no leads, state police spokeswoman Monique Bond said.
Bond said Santillan's vehicle ended up in a ditch and may have been out of sight of other rush-hour motorists.
"It may have been difficult for anyone to really take their eyes off the road to veer over and look," she said.
All eight victims had identification cards from a temporary employment agency in Chicago and may have been on their way to the Western suburbs for work, police said.
Three back-seat passengers who were not wearing seat belts died after they were thrown from the vehicle, according to police. The fourth fatality was a front-seat passenger who was buckled up.
Police said neither drugs nor alcohol played a role in the crash. DuPage County prosecutors said they do not expect to file more serious charges, but cautioned the investigation is ongoing.
"Definitely speed and a lack of seat-belt use is the cause of the fatalities," Windle said.
The sport utility vehicle had three rows of seats and at least seven seat belts. Police believe only two of the victims -- Santillan and her front-seat passenger -- were wearing them. They said Santillan was conscious and able to be interviewed after the crash.
The survivors were taken to area hospitals and all but the driver were in critical condition, according to Addison Fire Chief Don Markowski.
Windle said the speed limit in the area is 55 mph and there were skid marks at the scene. Investigators were working to reconstruct the crash and pinpoint the vehicle's speed.
Since 2010, there have been more than 800 traffic fatalities in Illinois involving children and adults who did not wear seat belts, according to statistics from the Illinois Department of Transportation.
Anyone with information on the Addison crash is asked to call Illinois State Police District 2 in Elgin at (847) 931-2405, ext. 205.