TUCSON, Ariz. (AP) — A University of Arizona student was fatally shot at an off-campus house party over the weekend, authorities said.

Three other people — a teenage girl, a man and a woman — were treated at a hospital early Sunday for injuries that were not believed to be life-threatening, Tucson police said in a news release.

Officers found 20-year-old Erin Jones shot outside the house about 1:40 a.m. Sunday, police said. She was taken to a hospital, where she later died.

University President Robert Robbins said Jones was a sophomore.

“Our deepest sympathies go out to Erin’s family in California and across the country, her friends, and her classmates in Tucson and Newport Beach, who are absorbing the heartbreaking news today,” Robbins said in a statement Sunday.

Investigators from the homicide unit are trying to determine what led to the shooting; several possible witnesses left the scene before officers arrived, authorities said.