(ANNA, IL) — Authorities say two adults and a child were killed in vehicle and semi-trailer accident on Interstate 57 in Southern Illinois. Illinois State Police say the accident happened at about 2:15 a.m. Wednesday in Union County. Police say a GMC Yukon SUV was traveling northbound when it collided with a semi-trailer traveling in the opposite direction. Both vehicles left the roadway. Authorities say the two adults and a child in a safety seat were killed. The Union County coroner pronounced them dead at the scene. Police say the semi-trailer driver refused medical treatment on scene. The victims weren’t immediately identified. Illinois State Police say they’re investigating. The interstate was closed for about seven hours for crash investigation and cleanup.