On Sept. 11, 2001, Jeremy Wallace was trimming weeds at a military pistol range in Muhlenberg County.
The Marshall County native had joined the National Guard only the year prior, and was stationed at the Wendell H. Ford Regional Training Center.
"One of the guys out there was listening to his Walkman. He heard it come across the radio," Wallace said. "It changed so many lives that day, pretty much instantly."
Wallace, 37, would eventually deploy to Iraq in 2006, a few years after an earlier deployment to Germany.
Wallace's company primarily performed convoy escorts and combat patrols.
"Being overseas, our company only lost one person to combat," Wallace said. "Over the years since we've been home, we lost three to suicide from PTSD."
Having dealt with PTSD himself, Wallace couldn't stand by and watch lives be lost. So he participated in Wounded Warrior activities, and in 2016 his own outreach was born.
"A Soldier's Heart Bluegrass and Muddy Watters" aims to use outdoor and music therapy to veterans who deal with PTSD -- weekend retreats usually incorporate water activities and music from whoever brings an instrument.
The group takes about six retreats a year, Wallace said, and he's seen group members progress significantly in socializing and talking about their experiences.
For Wallace, whose first humanitarian experiences came in the form of mission trips with his church, service is a deeply ingrained part of his character.
"I always looked at doing something like law enforcement, something with a service aspect," he said. "It just ended up being the National Guard at that time."
Wallace said he was motivated specifically toward PTSD therapy because he still has bad days when dealing with his own.
"It's like an injury to the mind, body and soul. It affects all of them," he said. "It's an invisible wound. It can get better over time, but it never really goes away."
The therapeutic combination of music and nature, Wallace said, help one "reach a calm where you can open up and communicate."
"It's just calm, peaceful and relaxing, and provides an atmosphere without hustle and bustle."
Despite much recent progress in addressing, treating and understanding PTSD, Wallace said he still finds a stigma associated with the condition.
"A lot of people don't want to have that label, but there's nothing to be ashamed of."
And for Wallace, who "wouldn't change a thing" about his military service, not using his own struggle to improve others' lives would be a waste.
"Any time you can take your struggle ... and you can help someone else through their struggles, it's the right thing to do."