The Downers Grove South High School student who died last week jumped from a moving vehicle two days before her death, according to police reports.

Kailee Miller, 18, of Downers Grove, died March 30, a spokeswoman for the DuPage County Coroner's office said. An official cause of death has yet to be determined.

According to a report from the Woodridge Police Department, Miller was at a party March 28 and had been drinking alcohol.

She and two other people – who police said had not been drinking – left the party and were driving at about 10 p.m. in the 8000 block of Janes Avenue, the report stated.

Miller said she was going to jump out of the vehicle, according to the report. The car was moving at about 25 mph when she jumped from the rear passenger door.

When police arrived at the scene, Miller was lying on the parkway, the report stated, and her breathing was shallow and abnormal.

She was transported to Advocate Good Samaritan Hospital for treatment, according to the report.

Jill Browning, director of communications for Community School District 99, said the district is "heartbroken" over the death.

"Kailee was an honor roll student, a member of the varsity soccer team and was well-liked by her classmates," Browning said in a statement. "Our entire community grieves for the Miller family and their loss."

South Principal Edward Schwartz said counselors were made available for Miller's teammates, teachers and any spring sports athletes at the school. Classes were not in session last week because of spring break.

Schwartz said a support system is in place for when students return to school Tuesday.

"It's tragic whenever we have a child die," he said. "It's not the natural way of life."