Two men were killed early Friday in a crash involving a semi-truck in northwest suburban McHenry County’s Dunham Township, according to police.

About 2:30 a.m., a 48-year-old man driving a 2003 Toyota Prius north in the 2000 block of North Route 23 crossed the center line for unknown reasons and struck a semi-truck head-on, the McHenry County Sheriff’s Office said.

The driver of the Prius and his 18-year-old male passenger were both killed in the crash, police said. The driver of the truck was uninjured.

The McHenry County Coroner’s Office hasn’t released details about the fatalities.