The crash occurred on I-90 in Rockford Saturday at around 1:20 a.m.
Illinois State Police said the truck driver hit a disabled vehicle. A woman driving the disabled vehicle was pronounced dead at the scene, according to state police.
The woman's 4-year-old was with her at the time. The child was taken to a nearby hospital for injuries that aren't life threatening, ISP officials said.
An investigation into the crash is ongoing.
No other details are known at this time.