Feis, 37, of Coral Springs, was one of the first victims publicly named in the aftermath of the massacre. The school’s football department announced the assistant coach and security guard’s death on social media.
“He selflessly shielded students from the shooter when he was shot,” the announcement read. “He died a hero and he will forever be in our hearts and memories.”
The Palm Beach Post reported that Feis was shot after throwing himself between students and the gunman. He died in surgery later that night.
Willis May, the school’s head football coach, said that he heard Feis respond via walkie-talkie to the original call reporting the shooting, in which someone asked if the loud noises they heard were firecrackers.
"I heard Aaron say, 'No, that is not firecrackers.' That's the last I heard of him," May said.
Feis appeared to be familiar with guns. His Facebook page, which has been turned into a memorial to him, depicts him as a gun enthusiast.
He once shared a news story about an Oklahoma school district that sought to deter gun violence by allowing some school administrators to carry guns on campus, and by posting signs warning the public of that fact.
In 2016, he also posted a Duck Dynasty-themed image that stated, “America doesn’t have a gun problem -- it has a sin and self-control problem.”
Feis also expressed pride in his position as a football coach.
“A coach will impact more young people in a year than the average person does in a lifetime,” one image read.
May described Feis as just such a leader, according to the Washington Post. The head coach called Feis a "hardcore" coach who loved working with the players.
He also described him as loyal and trustworthy.
"He had my back," May said, according to the Post. "He worked hard. Just a good man. Loved his family. Loved his brother. Just an excellent family man."
Broward County Sheriff Scott Israel also praised Feis, who he knew personally.
"I coached with him. My two boys played for him," Israel said during a Thursday news conference, according to NBC News. "I don't know how many adults will go, but you'll get 2,000 kids there. The kids in this community loved him. They adored him. He was one of the greatest people I knew. He was a phenomenal man."
Feis, who also played football at Douglas as a student, returned to his alma mater as a coach three years after his 1999 graduation, according to his bio on the school's athletics page. He spent his entire coaching career there.
A GoFundMe page honoring Feis was created Thursday and, in less than 24 hours, had raised more than $76,000 of the $100,000 goal. The cash will go to his family.
Feis is survived by his wife, Melissa, and their daughter, Arielle.
Like Feis, Hixon rushed toward the gunfire instead of away from it when the gunman started shooting. The 49-year-old athletic director, who lived in Hollywood, also filled in as volleyball coach and served as a security monitor when needed.
It was that security role that likely put him in the line of fire, friend and former colleague Dianne Sanzari told the Associated Press.
“While he was a security monitor, he did the very best he could to also serve in that athletic administrator role,” Sanzari told the news station. “He loved his family; he loved his job. Chris was just amazing.”
Hixon, who also served as the school's wrestling coach, pitched in wherever he could, according to those who knew him. His dedication led to him being named the Broward County Athletic Association's Athletic Director of the Year in 2017.
A Naval reservist, Hixon was also deployed to Iraq about a decade ago.
"He loved being an American and serving his country, and he instilled that in our kids," his widow, Debra Hixon, told CNN.
She said he also loved giving back to the community, particularly when it came to his students. He gave students rides or lunch money when needed, and would open up his family’s home to them.
"Every one of those students, he thought of as his own kid," Debra Hixon said.
Besides his wife, Hixon leaves behind his own two children, including a son with Down syndrome, ABC News reported.
“Chris is probably the nicest guy I have ever met,” Coral Springs High School Athletic Director Dan Jacob told ABC News. “He put the needs of everyone else before his own.”
Similar sentiments could be found on Debra Hixon's Facebook page, where she wished her friends a Happy Valentine's Day just hours before her husband was slain.
“Hope everyone has a warm and fuzzy day!” she wrote.
Instead of returned warm wishes, the comments on her post are comprised of condolences from friends and strangers alike.
"Debbi, Chris was one of the best people I ever had the pleasure to work with," one woman wrote. "My heart goes out to you and your family. MSD, the Broward school board and, indeed, the world, are all dimmer -- LESS -- today. My heart aches for you."
Since the shooting, Debra Hixon has posted several videos and images pleading for reform to the United States' gun laws. One image shows a rifle used by the Founding Fathers, which fired one or two bullets per minute.
It also showed an AR-15, which authorities said is the model of assault rifle Cruz used in Wednesday’s shooting. It fires 45 rounds per minute, the graphic states.
"Times have changed. Guns have changed," the image reads. "Our gun laws should change with them."
Beigel, 35, was killed as he ushered students into the safety of the classroom where he taught, the Palm Beach Post reported. Besides teaching geography, he also served as Stoneman Douglas' cross-country coach.
Beigel had locked the door of his classroom when the “Code Red” alert was sounded, but when he realized more students were outside his door, he acted quickly.
"(He) unlocked the door and let us in," student Kelsey Friend told "Good Morning America." "I thought he was behind me, but he wasn't. When he opened the door, he had to relock it so we could stay safe, but he didn't have a chance to."
Instead, he blocked the door with his body, another student, Bruna Oliveda, said.
"I don't know how we're alive," Oliveda said, according to NBC News.
Friend told CNN in an interview that Beigel will forever be her hero.
"I'll never forget the actions he took for me and for fellow students in the classroom," Friend said. "He was an amazing person, and I am alive today because of him."
Students and members of Beigel’s cross-country team mourned him on social media.
"I have said RIP (Rest in Peace) too many times in the past 24 hours, but RIP Coach Beagle (sic)," student Chad Williams tweeted. "You are a king and heaven got a good one. Rest easy."
Beigel, a native of Long Island, was also mourned by fellow counselors and former campers at Camp Starlight, a summer camp for children located in Starlight, Pennsylvania. Beigel served on the staff each year.
“The Starlight family is wrapping their arms around each other today, singing from our hearts to Starlight’s beloved friend and hero, Scott Beigel,” read a post on the camp’s Facebook page. “May every road rise up to meet your feet, and may the wind be at your back. May good friends supply every lack, until once more as friends we meet. Shalom, shalom.”
Former camper Sydney Reibman described Beigel as one of the most amazing people she’d ever met.
"He truly did touch the lives of every person who stepped onto camp," Reibman wrote on Facebook. "From making me laugh just by looking at me, or making a sarcastic comment (which I could never tell if he was actually kidding or not), to giving me tough love when I needed it, he knew how to make every situation fun and turn everything into something positive.
“My summers at camp never would have been the same without him.”
Matthew Perlman, who shared video of Kelsey Friend’s interview about Beigel’s heroism, wrote that Beigel had been his role model since his first summer at camp.
"Thank you for all the laughs and joy you brought into the world," Perlman wrote. "It's times like these where we need to love a little more and cherish the time we have together. Through the tears, our memories cling and surround you. Sending love to my entire Starlight family."
Lindsay Jennings called Beigel’s death a loss for everyone who knew him.
"But I know, like myself, that not one of you is surprised that our Scott stood in harm's way for his students. Of course he did," Jennings wrote. "Scott took ownership personally (of) each group of kids I watched him work with.
“He was one of the funniest and wittiest people I have ever come across, and Starlight wouldn’t have been the same without him for any of us.”