Uvalde teacher: ‘I will go to the end of the world to make sure things get changed.’

Robb Elementary teacher Arnulfo Reyes was shot twice by the gunman who murdered every child in his classroom on May 24 in Uvalde, Texas.

Reyes criticized the police response during the mass shooting and gave a vivid account of the tragedy in an exclusive interview with ABC News Tuesday.

He recounted the entire story from his hospital bed in San Antonio, ABC said.

Reyes said he told the 11 students in his room to get under their desks like they had practiced, but it wasn’t enough.

“I feel so bad for the parents because they lost a child,” Reyes told ABC anchor Amy Robach. “But they lost one child. I lost 11 that day, all at one time.”

Reyes told ABC about his thoughts on gun violence, vowing to do anything to make schools safer for students and staff.

“If that’s what I have to do for the rest of my life, I will do it,” Reyes said.

After showing the interview, Robach said Reyes will undergo another surgery Tuesday in his long road to recovering from his wounds.

Watch the entire interview above.

The exclusive was aired Tuesday morning on “Good Morning America.”