The last text message Darin Taylor Hoover sent his mother from Kabul's airport a year ago was short but one she still reads every day.

"Mamma I'm safe, I love you," the 31-year-old Marine Corps staff sergeant wrote as he worked to keep some semblance of order while thousands of desperate Afghans tried to get on the last few evacuation flights.

Taylor, as he was called by his family, was among the last 13 U.S. troops killed in Afghanistan. An Islamic State bomber blew himself up at an airport gate during the chaotic mission to evacuate Americans and at-risk Afghans before a complete U.S. military withdrawal.

Darin Hoover and Kelly Henson, Taylor's parents, have spent the past year trying to process the pain of losing their only son, re-reading the letters he left some family members and replaying the last time they saw him.

Their grief is mixed with anger, frustration and unanswered questions about why he was sent on that mission in the first place.

"It just aggravates me to no end that they put them in that situation that they should not have been in," said Hoover, who is a police officer.

On the first anniversary of the withdrawal this month, some U.S. officials and experts said there has not been public accountability for mistakes in the evacuation, which took place as the Taliban regained control of Afghanistan at the end of the United States' longest war.

'IT'S NOT REAL'

A linesman on his high school football team near Salt Lake City, Utah, Taylor was nearly 6 feet tall and had wanted to join the military since age 6. As an infantryman, he deployed to Afghanistan in 2011 and 2012.

Taylor's mother was used to being worried about her son, but saying goodbye to him in March 2021 before his last deployment felt different.

"I just had a horrible feeling. I hate to say it, but I just knew that was the last time," Henson said.

His deployment to the Middle East diverted to Afghanistan in August as the U.S.-backed government was crumbling.

About six months after their last meeting in California, Kelly was working from home on Aug. 26, 2021, when she saw news reports that there had been an explosion in Kabul and watched as the death toll ticked up to 13 American troops.

Later that night, as she was walking down to the laundry room, the doorbell rang and she knew it meant her son was among those killed.

"I remember just thinking this isn't real. This is not real," she said.

The past year has been punctuated with events around the country to remember Taylor and the other 12 troops who were killed that day, including a NASCAR race.

Taylor's family has slowly tried to return to everyday routines. Kelly has slowly started going back to work, only working 15 hours a week for now.

Darin has been able to immerse himself in his job, but there are times when his emotions overcome him.

"It could be something as simple as a song on the radio. It could be something as simple as talking to people and ... I'll get a rush of it," he said.

'YOU SHOULD BE HERE'

One of the toughest days was July 24, which would have been Taylor's 32nd birthday.

"Of all the 'firsts' we've had to endure, this day and the one coming up in the next month will really try me. You should be here damnit," Darin wrote on Facebook that day.

"The pain does not go away," he added.

The family, including his parents, sister and grandfather among others, went skydiving for the first time, something Taylor had wanted to do.

They started a scholarship in Taylor's name for students who demonstrate courage and community service, raising about $25,000 so far.

Later this month, the family will mark the first anniversary of his death on Aug. 26 at Arlington National Cemetery near Washington, D.C.

Military officials have contacted Taylor's parents several times to update them on an investigation into the deadly bombing that also killed at least 170 Afghans. But the parents say the Biden administration has not been willing to acknowledge that better planning and earlier action could have reduced risks for troops.

The Biden administration portrays the pullout and extraction operation - one of the largest airlifts ever - as an "extraordinary success" that wound up an "endless" conflict. A military inquiry said that the Kabul airport attack could not have been prevented with the resources on hand.

"What I'd like for them to do is say, 'Hey, this was mess-up, and we thank you for your son's service, and I'm sorry that it went down that way,'" Taylor's mother said.