Apalachee High School math teacher Cristina Irimie celebrated her birthday with her students on the day she and three others were fatally shot in Wednesday’s mass shooting.

“She decided to bake a cake and bring pizza to her classroom on the day she died so she could celebrate her birthday with her children,” her grieving friend Corneliu Caprar told CNN.

Irimie and her husband couldn’t have children of their own, so she considered her students her children, the friend said.

The Romanian-born teacher had previously turned 53 in August.

The other teacher killed that day, Richard Aspinwall, was shot when he went outside to see what was happening, a family friend told the newspaper.

She said some of his students ripped their shirts off to stop him from bleeding after he was beaten.

“His students pulled Ricky back into the classroom and tried to stop the bleeding with their own shirts and save him,” said the friend, Julie Woodson.

“If he hadn’t run away and taken the bullet… who knows what would have happened.”

Woodson added that Aspinall’s family wants the world to know: “Ricky was their core and he died a hero trying to save the lives of his students.”

Friends of Irimie, who immigrated to the U.S. more than 20 years ago, said she was known for her smile, her vibrant personality and her passion for teaching, which for her was not just a job but a calling.

“The first thing you see is her big smile. She was always smiling,” Father Nicolae Clempus, pastor of St. Mary’s Romanian Orthodox Church in Dacula, told Fox 5 Atlanta.

Clempus said Irimie’s husband is privately mourning the loss of his beloved wife.

“He is absolutely devastated and heartbroken. They were together all the time and had a very nice and beautiful family life,” the priest said.

“There is no logic in these kinds of tragedies,” he said of her senseless death, but added that she would live on in the hearts of her church family and others who knew her.

“We consider her a hero. Someone we will remember and look to as a role model for our generations.”