Christopher Roybal, left, is seen with his wife, Dixie Roybal, in this undated social media photo obtained by Reuters, Oct. 3, 2017.
Christopher Roybal, left, is seen with his wife, Dixie Roybal, in this undated social media photo obtained by Reuters, Oct. 3, 2017.

A few months before he was killed in the deadliest mass shooting in modern U.S. history, Christopher Roybal tried to explain the toll of combat in Afghanistan on those serving in the American military.

"What's it like to be shot at? It's a nightmare no amount of drugs, no amount of therapy and no amount of drunk talks with your war veteran buddies will ever be able to escape," the Navy veteran wrote on Facebook in July.

After surviving 11 months in Afghanistan, Roybal, 28, was killed on Sunday night along with 58 others during a shooting spree by a Nevada man who rained fire from a 32nd-floor window of the Mandalay Bay hotel into a crowd at a nearby country music festival.

"I just had the worst feeling. His guard was down. This isn't where he was expecting something bad to happen to him," his wife, Dixie Roybal, told Reuters on Tuesday.

She had stayed home in Corona, California, while her husband celebrated his upcoming birthday with his mother, Debby Allen, in Las Vegas.

Debris litters the festival grounds across the str
Debris litters the festival grounds across the street from the Mandalay Bay Resort and Casino in Las Vegas, Oct. 3, 2017.

Roybal served in the Navy from 2007 to 2012 and was in Afghanistan from July 2011 to May 2012 with a working dog team, military records show.

His wife said that although Afghanistan still haunted him, he had an adventurous spirit and managed to find joy in life.

"He was always going somewhere, doing something, calling friends," she said. "He just loved music in general. He was always singing something. He was the best at karaoke."

Among Roybal's many tattoos was one on his arm celebrating the city of Las Vegas, where he had once lived, his wife said.

After the military, he worked at a gym called Crunch Fitness in Corona, a job that he loved.

His wife said they met shortly after high school and eventually fell in love and married. They did not have any children.

On Sunday, Roybal and his mother went to the Route 91 Harvest festival near their hotel. As country music singer Jason Aldean played, a barrage of high-powered shots rang out, and they were separated in the chaos that ensued.

Allen was frantic to find her son and posted on Facebook late that night: "I just can't find Christopher Roybal anywhere. He's not answering anyone's phone calls."

When she finally heard the tragic news, she wrote: "Today is the saddest day of my life. My son Christopher Roybal was murdered last night in Las Vegas. My heart is broken in a billion pieces."

Back in California, Dixie Roybal had been frantically trying to reach her husband by text and phone. It was Monday when she was learned her husband had been shot in the chest and his name finally appeared in the official list of casualties.

"This isn't something that should have ever happened," she said. "It's horrible."

Roybal's family planned to take his body home to California.

A GoFundMe page had raised $23,541 in 19 hours for funeral expenses.

Matthew Austin, who joined the Navy with Roybal when they were "just boys," said on Facebook he was angry about his friend's death.

"It breaks my heart and infuriates me that a veteran can come home from war unharmed and events like these occur," he said.