PUNTA GORDA, Fla. — A woman was fatally shot by an officer while participating in a “shoot-don’t shoot” exercise during a two-hour citizens academy hosted by the Punta Gorda Police Department in southwest Florida.

Police Chief Tom Lewis said the shooting happened Tuesday night as two of the 35 participants were randomly selected to take part in a live roleplaying scenario “in which they make decisions on using simulated lethal force.”

Lewis said Mary Knowlton, a librarian, was “mistakenly struck with a live round.”

“I am devastated for everyone involved in this unimaginable event,” Lewis told reporters during a late-night news conference at the police department. “If you pray, please pray for Mary’s family, and for the officers who were involved. Everyone involved in this accident is in a state of overwhelming shock and grief.”

Knowlton was taken to a hospital in nearby Fort Myers, where she was pronounced dead.

The citizen’s academy is a free, eight session course designed to provide insight into city government, according to the city’s website.

The Florida Department of Law Enforcement is investigating, Lewis said. He declined to identify the officer involved in the shooting, but said he’s been placed on administrative leave.

A profile on a Facebook page that appeared to be Knowlton’s said she lives in Punta Gorda, but had been a librarian at Scott County Public Library in Savage, Minnesota. She studied library science at Minnesota State University in Mankato, Minnesota, and elementary education at George Mason University in Virginia. The profile information said she’s from Austin, Minnesota.