Illinois State Police said two people were killed and two others injured after a car fell at least 70 feet off the Stephenson Highway and crashed onto the road below.
The car was heading inland in Stephenson when Illinois State Police said at about 4 a.m. that it had lost control near Ashland Street and crashed into and over the concrete wall. The car landed on the street below on Archer Street and Robinson Street.
Police said a total of four people were in the car and two people were killed, a 27-year-old man and a 22-year-old woman. The Chicago Fire Department said a 21-year-old woman and a 25-year-old man had been taken to Struger Hospital in critical condition.
The authorities did not reveal the identities of the two dead.
The cause of the accident was not known, but police said their preliminary results showed that the car was traveling at high speed. Police also confirmed an ice bank on the I-55 as the vehicle lost control, but it is unclear if that was a factor in the accident.
Police said the car also hit a light tower and lights were turned off in Stephenson in both directions between Ashland and the Dan Ryan Highway.
Safety advocates said the horrific accident is a reminder of the dangers of traveling during winter weather. AAA experts said drivers should monitor their speed, leave a great distance between cars, and make sure not to use the brakes on snow to avoid slipping, slipping and slipping.