A prison work detail began as usual Monday morning, but an unexpected turn of events ended with a guard, experiencing a possible stroke, being airlifted to Savannah, thanks to a quick-thinking prison inmate who likely saved his life. Bulloch County Correctional Institute guard Oscar Vickery and inmate Darrell Mumford were picking up solid waste in the Portal area when Vickery began acting strangely, said Warden Chris Hill. Vickery, who Hill said “is in his 60s,” was driving a solid waste truck with Mumford as a passenger when Vickery began showing signs of a possible stroke, Hill said.