Two sisters are dead and 12 others were injured in an eight-vehicle accident on Interstate 55 Tuesday evening.

Hailey Bertels, 20, and her 17-year old sister, Madisen, both of Staunton, were killed when, according to witnesses, the driver of a semi struck seven vehicles at highway speed near Hamel. Madisen was driving the vehicle, a 2010 Kia Forte, while traveling south on I-55 at Milepost 27.5 near Hamel. Hailey was in the back seat of the car at the time of the accident. Both girls were wearing their seatbelts.

12 others were injured in the accident and taken to multiple area hospitals. At least two sustained life-threatening injuries.

The accident occurred at 6:14 p.m. Tuesday. It remains under investigation by the state police.