A Georgia Department of Corrections officer was killed in the line of duty Sunday at a prison in Tattnall County.

According to a release from the GDC:

Correctional Officer Robert Clark, 42, was escorting two offenders from the dining hall at Smith State Prison when one of them attacked him from behind with a homemade weapon. The other prisoner stepped in to assist Clark and was also assaulted.

Both men were taken to local hospitals, where Clark succumbed to his injuries.

“The entire GDC team is mourning the loss of one of our own and we collectively express our deepest condolences to Officer Clark’s family and friends,” said Commissioner Tyrone Oliver. “We will support them as they navigate this tragedy over the coming days, weeks and months.”

Clark had just started work as a corrections officer in April.

The inmate who helped him, Marko Willingham, 40, remained hospitalized Sunday with non-life threatening injuries.

Layton Kiev Lester, 32, will be charged in the assault and resulting death of Clark, as well as the assault of Willingham.

Lester is already serving a life sentence for murder committed during an April 29, 2007, burglary and armed robbery in Tift County.

Willingham also is serving a life sentence, for a 2002 murder in Walton County. He’s been in prison since June 5, 2003.