STE. GENEVIEVE, Mo. (AP) — Grief counselors are assisting students at a southeast Missouri high school after two classmates were killed in a rollover accident on Interstate 55.

The crash happened Sunday night in Jefferson County. A car driven by 17-year-old Danielle Pfaff went off the road, hit a tree and flipped. Pfaff and a 16-year-old passenger, Zoe Rhymer, were taken to a suburban St. Louis hospital. A spokeswoman at Mercy Hospital confirmed Monday that both died.

A third passenger is hospitalized with moderate injuries.

A crisis counseling center was set up at Ste. Genevieve High School to help grieving students.