The first reminder of all the things Nicholas Dworet would miss was on a whiteboard in his room, where he wrote his goals and inspirational quotes.

“It had things like ‘grad bash'...written on it,” Mitch Dworet, Nick’s father, said. “It started at prom, which was very difficult. Then we got his graduation pictures.”

Nick, a swimmer with aspirations of Olympic gold and an infectious smile, was among four seniors killed when a gunman opened fire at Marjory Stoneman Douglas High School in Parkland, Florida, on Feb. 14, leaving 17 students and teachers dead.

His parents are now coping with the final high school milestone their son won’t get to experience: graduation.

Watch “Voices of Parkland: Healing Out Loud” premiering on Sunday at 10 p.m. ET on MSNBC

At the school’s commencement ceremony at the BB&T Center in Sunrise, Florida, on Sunday — the final day of "Wear Orange Weekend," an awareness campaign organized by gun violence prevention advocates — Dworet and the other three seniors killed in the shooting will be remembered, along with two others in the class who died before this year, one of illness and the other by suicide.

The school has not released plans for how the six students will be memorialized, but the Dworets said some of their son’s swimming teammates and friends, many of whom he mentored, will be wearing his name on their graduation caps.