Updated at 8 p.m.
The accident occurred shortly before 7:30 p.m. Friday, according to sheriff's Deputy Joshua Morales.
Shelly Graesser was trapped beneath an antique tractor on rural land off Cantrell Road, Morales said.
"Preliminary investigation indicated Graesser was alone while operating an antique tractor on her property, when the tractor overturned and caused her to sustain fatal injuries," Morales told Patch.
The Temecula Police Detective Bureau and Riverside County Coroner are investigating the incident, Morales said.
Funeral arrangements were pending today for Shelly Graesser, assistant principal at Vail Ranch Middle School in Temecula.
Graesser, who was in her late 30s, was killed Friday evening when the
tractor she was riding on flipped over at her family's berry farm -- Temecula Berry -- near Temecula's Wine Country, according to sheriff's deputies.
Vail Ranch Principal Kevin Groepper said that grief counselors will be
on the campus beginning Monday to meet with students and staff members.
Graesser is survived by her husband, Mike, and two children, Daisy and
According to the school web site, Graesser joined Vail Ranch at the
close of the 2003-04 school year. She earned her undergraduate degree at Point Loma Nazarene University in San Diego and completed her master's degree ineducational administration at Cal State San Bernardino.
Graesser taught eight years of math and science in middle school and
elementary school in the Temecula Valley Unified School District before becoming Vail Ranch assistant principal.
-- City News Service contributed to this report.