The Iowa high school principal who was critical wounded while protecting his students from a 17-year-old’s mass shooting attack earlier this month died from his injuries Sunday morning.

A GoFundMe raising money for Dan Marburger’s family made the tragic announcment.

“Although the news has not fully set in yet, Dan Marburger gave the ultimate sacrifice,” a post on the fundraising website said. “After 10 days, he lost his battle and this tragedy took his life.”

Marburger was the only adult shot when Dylan Butler opened fire at Perry High School 20 minutes before the start of school on January 4, the first day back from winter break, as CrimeOnline reported. Middle school students, who share a building with the high school, were present at a breakfast program, and 11-year-old 6th grader Ahmir Joliff died after he was shot three times.

Four other students were wounded before Butler shot himself. Butler was armed with a pump action shotgun and a small-caliber handgun, and investigators found and disarmed a homemade bomb in the school.

Marburger had been the school’s principal since 1995, according to KCRG. The Iowa Department of Public Safety called Marburger’s actions heroic, saying he “acted selflessly and placed himself in harm’s way in an apparent effort to protect his students.”

For the latest true crime and justice news, subscribe to the ‘Crime Stories with Nancy Grace’ podcast.

[Featured image: Dan Marburger/Facebook]