A DeKalb County Sheriff’s detention officer recruit died Wednesday after becoming ill during training, officials said.

George Ward, 29, was on his second day of work Tuesday when he became dizzy, sheriff’s office spokesman Sgt. Adrion Bell said.

“They were doing the initial physical fitness training,” Bell said, referring to the fitness assessment test the 12 recruits were taking.

Ward was taken back to the jail, where medical staff treated him before an ambulance took him to DeKalb Medical Center, where he died the next day.

The cause of Ward’s death remains unknown. The DeKalb County Medical Examiner’s office will perform an autopsy Thursday.

“This is the first time that such an incident has occurred during my 12 years as sheriff,” Sheriff Thomas Brown said in a statement. “Though we had only known him for a few days, the hearts of the men and women of the Sheriff’s Office are heavy.”

County law enforcement officers must pass a medical clearance and a “Physical Efficiency Battery Test” to be eligible for employment, sheriff’s officials said.

Ward had just begun the Basic Jail Operations Academy, a state-sanctioned course taught by sheriff’s staff, Bell said.

Once the recruits complete the three- to five-week training, they are certified as detention officers through the Georgia Peace Officer Standards and Training Council.