A member of the Lexington County Sheriff’s Department’s dive team died Thursday during an underwater training session on Lake Murray.

Jillian Olson, 29, began her career as a Lexington County deputy in 2021. After more than a year as a patrol deputy, she transferred to a warrant deputy position. Olson was promoted to master deputy in the Warrant Division in 2025. She has been a member of the LCSD dive team since 2024.

“Our hearts are broken by the loss of a valuable member of the Sheriff’s Department,” Lexington County Sheriff Jay Koon said. “Jillian exemplified commitment and service. She faithfully carried out her duties and selflessly worked to make those around her better.”

The Lexington County Sheriff’s Foundation named Olson the outstanding judicial services deputy of the year at its annual awards banquet last spring, according to Koon.

“The foundation recognized Jillian for showing exceptional initiative and leadership by, on her own time, developing reference guides and document templates for use by judicial services deputies,” Koon said. “The tools Jillian developed improved deputy training and operational workflow.”

Olson, a resident of Lexington, received the Sheriff’s Department’s tactical operations support award in 2023. She was scheduled to receive the department’s five-year honorable service award next month.

A native of Illinois, Olson graduated from Western Illinois University in 2019 with a bachelor’s degree in law enforcement and justice administration. She completed a master’s degree in student personnel services from the institution in 2021.

“Jillian’s dedication to her community and department is well-documented with awards and recognitions,” Koon said. “She’ll be most remembered for what she did with no fanfare. Her decision to join our dive team is just one example of her going above and beyond.”

The South Carolina Department of Natural Resources is leading the investigation into Olson’s death, with assistance from the South Carolina Law Enforcement Division. The Lexington County Coroner’s Office is conducting its own investigation to determine Olson’s cause and manner of death.

“I am grateful to DNR, SLED and our county coroner for the sensitive and respectful way they’ve handled everything,” Koon said. “I would also like to express my thanks to the countless public safety agencies that responded without hesitation from across the whole state to help us in our time of need.”