Nick Tullier, a Baton Rouge sheriff’s deputy who was shot in the head and stomach during a July 2016 ambush that killed three other law enforcement officers during a summer of protests over the police killing of a Black man, died Thursday at age 47.

Tullier’s death was announced on the Facebook page of his father, James Tullier, and on a companion page dedicated to Tullier’s effort to recover in the years since the shooting. They did not mention the cause of death, but Tullier had struggled for years to recover from the 2016 shooting.

Louisiana Gov. John Bel Edwards ordered that flags fly at half-staff over the Capitol and other public buildings in East Baton Rouge Parish until sunset Friday. He called Tullier, a corporal in the East Baton Rouge Parish Sheriff’s Office, and the other officers shot in the July 17, 2016, shooting “true heroes.”

The Sunday morning ambush came less than two weeks after Alton Sterling, a Black Baton Rouge resident, was fatally shot in a struggle with two white Baton Rouge police officers outside a convenience store on July 5. Video of Sterling’s killing spread on social media and led to protests against the police in Baton Rouge and beyond. No officers were ever charged for Sterling’s death, although the local government reached a $4.5 million settlement with his family years later.

Two days after the Sterling shooting, a sniper in Dallas killed five police officers and wounded seven others during protests over the shootings of Sterling and the July 6 shooting death of Philando Castile.

The July 17 ambush ended when the suspect was shot and killed. He was identified as Gavin Long, 29, of Kansas City, Missouri, a Black military veteran. He died after killing Baton Rouge police officers Montrell Jackson and Matthew Gerald and another East Baton Rouge Parish Sheriff’s deputy, Brad Garafola,

“I am heartbroken at the passing of a true hero, Cpl. Nick Tullier this morning,” East Baton Rouge Parish Sheriff Sid Gautreaux said in a statement. “Nick’s injury was a result of his selfless actions to courageously answer the call to protect and serve. For nearly six years he has defied all odds in recovery through his unwavering tenacity.”

Tullier, a father of two, had 18 years of service with the sheriff’s department when he was shot.