A young Watauga County sheriff’s deputy – and soon-to-be father – was fatally wounded during a shootout that also left his shooter dead early Thursday near Boone, authorities said.

William Mast Jr., 23, who had been a deputy for about three years, was shot while responding to a 911 call around 1:15 a.m. Thursday.

The Watauga County Sheriff’s Office said the incident happened at a mobile home in the 2100 block of Hardin Road, off U.S. 421. That is in the Deep Gap community, about eight miles northeast of downtown Boone.

Authorities said they had received a 911 call from a home there, but no one spoke when dispatchers answered the call.

Mast and another deputy went to the home, authorities said. That’s when a man opened fire, striking Mast.

The second deputy returned fire, killing the man, the Sheriff’s Office said.

Mast was rushed to a hospital but died Thursday morning of his injuries.

According to reports, Mast’s shooter was identified as 33-year-old Mitchell Allen Trivette. He also died as a result of his injuries.

A search of public records reveals Trivette lived at a home on Hardin Road and had no criminal convictions in North Carolina. A woman who answered the phone at one of Trivette’s relative’s homes declined to comment.

The Sheriff’s Office has not said what might have led to the shooting, saying that the N.C. State Bureau of Investigation is overseeing the investigation.

“It is a sad day for the Watauga County Sheriff’s Office and the Watauga County community,” Sheriff Len Hagaman said. “Officer Mast was a friend and asset to our force and to his community.”

Mast’s wife, Paige, is pregnant, according to several reports. In May, Paige Mast posted a photo on Facebook of a sonogram image.

Mast was assigned to the Sheriff Office’s patrol division and would have celebrated his 24th birthday next month. He grew up in Watauga County and was well-liked by his fellow officers, said Sgt. Shane Robbins of the Boone Police Department, which is assisting the Sheriff’s Office.

“He was just a tremendous officer and a tremendous person,” Robbins said.

Kathleen Baker wrote on her Facebook page that her father worked in law enforcement and he thought of Mast like a son. She described Mast as “one of the most amazing, sweetest and genuine people I have had the privilege of meeting through my father.”

“William was always stopping by the house to bring us a jug of sweet tea,” she wrote. “He would bring me some sort of pastry from somewhere, and most special of all, he would stop by to talk to us and to tell us stories…”

In a statement posted on Watauga County’s website, County Manager Deron Geouque said Mast was killed while “protecting and serving our county.”

“Words cannot adequately portray how deeply saddened the county, the community and the Mast family are over this tremendous loss,” Geouque said.

Staff researcher Maria David contributed.