CNN — (CNN) -- The Nevada teacher credited with shielding students from a pistol-wielding classmate was a Marine veteran who survived distant battlefields but died on a school playground.
Michael Landsberry, a 45-year-old math teacher at Sparks Middle School, was gunned down Monday by a 12-year-old student with a 9 mm semiautomatic pistol. The shooter, whose identity has not been released, also wounded two 12-year-old students before turning his weapon on himself. The entire tragedy unfolded in a mere three minutes.
Authorities on Tuesday confirmed that Michael Landsberry walked toward the shooter after the boy had already wounded one schoolmate in the shoulder.
"Mr. Landsberry's heroic actions, by stepping toward the shooter, allowed time for other students in the playground area to flee," Washoe County School District Police Chief Mike Mieras said.
Reggie Landsberry said his brother Michael, like their father a former Marine, probably was trying to talk the boy out of shooting.
"That was the kind of person that Michael was," Reggie Landsberry said. "He was the kind of person that if somebody needed help he would be there."
A student who witnessed the shooting said Michael Landsberry was trying to make the boy put his weapon down. He did not. "He took the shot right then and there." Landsberry died of a gunshot wound to the chest. The shooter then wounded another boy in the abdomen before taking his own life.
A Facebook memorial page posted in Landsberry's honor had more than 15,100 likes on Tuesday afternoon.
Among the comments:
"Once a hero, always a hero! RIP."
"God bless you for the greatest act of courage and love."
"From one Air Force vet to a USMC vet, I salute you. Rest in peace, brother."
Thousands more honored the slain teacher on a "Rest Easy Mr. Landsberry" page.
On a website for his students, "Mr. Landsberry's Math Class," the slain teacher had posted pictures of himself hiking in the wilderness and standing with a weapon beside an armored vehicle.
"One of my goals is to earn your respect while you earn mine," he wrote in a message to students. "I believe that with mutual respect that the classroom environment will run smoothly."
Reggie Landsberry said caring for others was something he and his brother learned from their father, who served in the military for 22 years. Michael Landsberry loved teaching and coaching at Sparks Middle School, his brother said.
"He was just a good all-around individual," he said.
Michael Landsberry went to Afghanistan on several tours as a member of the Nevada Air National Guard, his brother said.
Sparks Mayor Geno Martini called the loss of Landsberry "devastating."
"It's very unfortunate that (the life of) someone like that, who protected our country over there and came back alive ... had to be taken at his work, at a school," Martini said.
The mayor said Landsberry "was a brave man, obviously, to stand up in front of a kid like this and put his life on the line."
Landsberry joined the Marine Corps in 1986, attained the rank of corporal and served as a field wireman, Marine spokeswoman Maj. Shawn Haney said.
Here is another comment on the Facebook memorial page for Landsberry: "A lot of lives saved by this Marine. May he guard the gates of heaven. Semper Fi, Sir."
"Semper Fidelis" is the motto of the U.S. Marine Corps. Often shortened to "Semper Fi," it is Latin for "Always Faithful."