A Tuesday night, single-car crash near Huntley has left a young Algonquin woman dead and two young Huntley men critically injured, authorities said.
Meanwhile, officials are neither naming a juvenile girl who also was injured in the crash nor releasing her medical condition.
Megan E. Hartigan, 20, of Algonquin, died after the crash, while Jonathan J. Lombard, 21, of Huntley and Ryan W. Hanks, 18, also of Huntley, were listed in critical condition Wednesday afternoon.
Hartigan is being remembered as a friendly person who wowed people with her bright smile.
An autopsy indicates she died of head and chest trauma as a result of being ejected from the car she was in, said Rob Locke, deputy coroner for the McHenry County Coroner's Office.
Her toxicology results won't be available for at least a month, Locke added.
Hartigan was a recent graduate of Jacobs High School and received her diploma in 2010, Principal Ami Engel said.
Students and teachers have talked about Hartigan throughout the school day, Engel said.
"She actually kept a pretty low profile," Engel said, adding that Hartigan wasn't involved in any sports or other activities. "But she was really friendly, she had a really bright smile. She was really fun loving. She always like to make sure she was dressed just so and spent a lot of time with her friends."
The school has made counselors available for students and staff and also will hold a moment of silence in Hartigan's honor later this week, Engel said.
The wreck occurred at 10:45 p.m. in the 14600 block of Marengo Road near Huntley, said Deputy Amy Knop, public information officer for the McHenry County Sheriff's Office.
Police say the 2004 Hyundai Elantra was headed west on Marengo Road when for unknown reasons it left the roadway, hit a culvert and rolled over.
All four people were ejected from the car; none was wearing a seat belt, Knop said. It is not known who was driving.
Hartigan was taken to Centegra Hospital in Woodstock, where she later died. Her funeral arrangements are pending.
Lombard and the girl were taken to Sherman Hospital in Elgin, while Hanks was taken to Provena St. Joseph Hospital in Elgin.
Authorities continue to investigate the crash, including its cause. If you were a witness to the crash, call the sheriff's crash investigation unit at (815) 338-2144.
Staff writer Lee Filas contributed to this report