The crash happened around 4:45 a.m. Monday on Route 30. The DeKalb County sheriff's police say the car, which was driven by 18-year-old David Sak, was leaving a graduation party and heading to a campground.
The car was traveling westbound when it crossed the center line and struck the semi-truck. Authorities say Sak was pronounced dead at the scene. One of his passengers, 18-year-old Arthur Orlowski, was flown to a Rockford hospital where he died a short time later.
The car's other passenger, 18-year-old Diego Valdes, was taken to an area hospital.