TAMPA, Florida (WFLA) — Heartache swept the nation Tuesday when multiple children were gunned down in their Texas classroom. The massacre of at least 19 students and two teachers at Robb Elementary School in Uvalde, Texas sent shockwaves across America, echoing past school shootings.

Throughout the afternoon, more and more details were released, each one worse than the last. The facts were unfathomable. While the massacre prompted endless questions, one was asked over and over again: Why would someone do this?

For Zaxh Hibschman, living with a similar pain for four years, the circumstances were achingly familiar and hit close to home. He survived the mass shooting at Marjorie Stoneman Douglas High School in Parkland, Florida, on Feb. 14, 2018.

He was in the school that day and heard the gunshots come closer and closer, his heart pounding so rapidly that he could hear it in his ears. Hibschman was a junior when the shooting happened, and he remembers with vivid detail the exact moment he heard the unmistakable sound of gunshots.

Gunshots came in quick succession, one after the next, and they kept coming. “I had the thought that I might not make it out of that school alive,” Hibschman said. Within seconds, he said felt the intensity of a “fight or flight” response propelling him to find a safe place. He described what happened next as “chaos.”

He heard screaming students, their shoes rapidly hitting the pavement as gunfire chased them through buildings and classroom. Friends and classmates ran past each other in a horrifying blur, racing for cover. Hibschman said he knew his only chance for survival was to get to his homeroom, a seemingly impossible task. But the will to live, he said, was instinctual, based on raw emotion and crippling fear.

The combination saved his life. His homeroom became a fortress. He was crammed into a tiny closet with 15 people, spending hours in the dark. When law enforcement found them—their voices breaking the uneasy silence—the shooting was over, but the fear lingered.

Hibschman remembers the immense relief he felt when he heard the sound of SWAT team members approaching, but those emotions eventually gave way to anxiety and phobias of crowds and concerts. He now lives with PTSD while working through his senior year at the University of Florida.

When he heard what happened in Texas on Tuesday, all the emotions and fear from Parkland came back. He said he knows countless families are hurting right now, and his heart goes out to them. His message to Texans: Lean on each other because that’s where you find strength. But, he says, it will take time.

“Grieving is not a sprint, it’s a marathon,” Hibschman said. “Cherish the moments you have with everyone.”

He added that he hopes families and survivors reach out for compassion and support. “It’s definitely in these moments you realize love is stronger than hate. A strong and loving community is everything,” Hibschman said.