Deputy, 29, Dies During Underwater Training Exercise Shortly After Celebrating Her 100th Dive

The Lexington County Coroner’s Office is conducting an investigation to determine Olson’s cause and manner of death, the department added.

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

Authorities said Olson, a resident of Lexington, joined the department as a deputy in 2021, and later became a warrant deputy more than a year later. A member of the sheriff’s dive team since 2024, Olson was promoted to master deputy in the warrant division last year.

Olson received a tactical operations support award from the sheriff’s department in 2023 and was scheduled to receive a five-year honorable service award this month.

Originally from Illinois, Olson graduated from Western Illinois University in 2019 with a bachelor’s degree in law enforcement and justice administration. She later received a master’s in student personnel services from the same university two years later.

A published obituary noted Olson’s zeal for life outside of her professional duties.

“She loved spending time on the lake – paddleboarding, floating in the sunshine, and diving,” the memorial tribute noted. “She had recently celebrated her 100th dive, a milestone reflecting her adventurous spirit and love of exploring the underwater world. She was endlessly curious and determined. Jillian took immense pride in her home and eagerly tackled projects she had never done before – teaching herself new skills through research, persistence, and hard work.”