SC deputy dies during dive training on lake she considered her refuge

A routine day of dive team training for a South Carolina sheriff’s department took a tragic turn when a deputy died during underwater exercises.

Master Deputy Jillian Olson, 29, died in an underwater training session on Lake Murray on Thursday, the Lexington County Sheriff’s Department said.

A member of the department’s dive team since 2024, Olson had spent more than 100 hours underwater, according to officials. The Lexington County Coroner’s Office is investigating to determine her cause and manner of death.

The South Carolina Department of Natural Resources said its Investigations Unit and Aquatics Investigation and Recovery (AIR) team led recovery efforts and were assisted by the South Carolina Law Enforcement Division. The departments did not return The Post’s requests for comment

“I would 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,” Lexington County Sheriff Jay Koon said in a statement.

Olson joined the sheriff’s department in 2021 and was promoted to master deputy in the warrants division in 2025. A native of Illinois, Olson had a deep passion for law enforcement, Pastor Frank Anderson of St. Michael Lutheran Church told The Post. 

Anderson, who said he’s known Olson and her family for decades, said her calling to serve and protect was informed by her Christian faith.

“She had a deep faith and I think that deep faith was the motivation for her to want to be a helper and serve other people,” said Anderson of Olson, who he baptized himself. 

“She had an altruistic heart,” the pastor added.

The deputy’s decision to join the dive team was “just one example of her going above and beyond,” Sheriff Koon said.

Olson was scheduled to receive a five-year honorable service award next month. 

Olson graduated from Western Illinois University in 2019 with a bachelor’s degree in law enforcement and justice administration.

She also held a master’s degree in student personnel services. 

Lake Murray, a man-made reservoir constructed in the 1920s to produce hydroelectric power, is located just west of Columbia. It covers over 48,000 acres of surface water and has roughly 650 miles of shoreline. Its average depth is about 41 feet, but parts of the lake reach depths of nearly 200 feet.

Olson — who will be laid to rest on Wednesday — often spent time on Lake Murray, both for work and for recreation.  

Her family had recently purchased a house on the lake, and it was there that she spent her free time kayaking, paddle boarding and jet skiing, Anderson said. 

“She enjoyed the serenity and the quiet of the lake in the midst of her busy career as a sheriff’s deputy,” the pastor said.