He died after jumping in front of a student and the shooter, pushing the student through a door and out of danger.
He leaves behind a wife and young daughter.
"You went out of your way to make everyone feel good and that smile… that smile lit up every single room you walked into."
His brother confirmed his death on Instagram early Thursday, writing, “Words cannot describe my pain… I know you’re in a better place.”
Friends started posting tributes to him early Thursday. One wrote, “i love you so much, i hope you’re in a better place."
A friend wrote, "We walked into Kindergarten together, so knowing that you won’t be walking across the state at graduation with me in a few months is devastating and heartbreaking."
An administrator from a nearby school described him as "probably the nicest guy I have ever met" and someone who "would give you the shirt off his back."
A student said Beigel unlocked the door to his classroom and let her in. “When he opened the door, he had to relock it so that we could stay safe but he didn’t get the chance.”
"A knife is stabbed in my heart. I wish I could of taken those bullets for you. I will always love you and your memory will live on forever.”
“Our Luke was a precious child, who just went to school yesterday not knowing what was to come,” another relative said.
“She was the sweetest soul ever,” said a color guard instructor. “She was kind, caring, always smiling and wanting to help.”
“her life was taken way too soon and i have no words to describe how this feels," a friend wrote on Facebook. "Rest In Peace my beautiful angel. you are and forever will be loved."
“I was in the same classroom as this beautiful soul, she was so bright and had her entire life ahead of her. She was someone we all praised for her intelligence,” a friend wrote on Facebook.
“He wasn’t supposed to die,” his cousin said. “He was supposed to grow old with me.”
"There are no hashtags for moments like this, only sadness," she wrote. "Our hearts are with [her family] and all the families touched by this tragedy."
“RIP Cara, and fly with the angels. You will be greatly missed, and we will always love you and celebrate your beautiful life.”
“He will be missed immensely. Everybody is just broken up and beyond shocked… His family adored him and we're all really just in shock.”
"Though she was some what reserved, she had a relentless motivation towards her academic studies, and her soft warm demeanor brought the best out in all who knew her."