Authorities have identified four women killed in a rollover crash early Thursday on I-290 in Addison.
The victims -- Juanna Anaya, Maria Duran, Donna Mejia and Maria Orellana -- all died of multiple traumatic injuries, the DuPage County coroner's office said Friday.
Anaya and Duran both lived in Chicago and were each 44 years old, officials said. Authorities are still trying to pinpoint the ages and hometowns of Mejia and Orellana. Police previously said all of the victims were Chicago residents.
The quadruple fatality happened about 6 a.m. when a Ford Explorer driven by 31-year-old Margot Santillan of Chicago went off westbound I-290 and rolled over several times.
Monique Bond, spokeswoman for the Illinois State Police, said investigators confirmed Santillan was speeding, and a crash reconstruction effort was wrapping up Friday.
"It appears speed is the sole contributing factor," Bond said.
Police said three of the victims weren't wearing seat belts and died after being thrown from the vehicle. Four survivors, including the driver, were hospitalized with injuries.
Santillan was cited for improper lane use, failure to reduce speed, driving without a valid license, driving without insurance, and driving on a suspended license.
The crash occurred roughly a mile west of Route 83. Police said Santillan's vehicle went off the north side of the road and rolled over several times, coming to rest in a ditch.
All eight of the victims had identification cards from a temporary employment agency in Chicago and may have been on their way to work in the suburbs, police said. The survivors -- Santillan and three men -- range in age from 28 to 51.