Nate Holley had to arm himself with a classroom bat when two older students opened fire in his suburban Denver school.
A 12-year-old boy caught up in a US school shooting has revealed he armed himself with a baseball bat because he wanted to "go down fighting".
Sixth-grader Nate Holley was at STEM School Highlands Ranch in Denver on Tuesday when two students opened fire in the school, killing one and injuring eight others.
"I had my hand on a metal baseball bat just in case," Nate told CNN.
"Because I was going to go down fighting if I was going to go down."
Nate said he heard gunshots shatter windows, sirens ringing, and his teacher urging the students behind a desk and then into a closet.
"It was really chaotic," he said.
"Most of the kids didn't know what to do."
The shooting happened just 8km from Columbine High School, where 12 students and a teacher were murdered 20-years-ago in one of the worst school massacres in the country's modern history.
Several of the victims were taken to hospital in critical conditions, and one 18-year-old male student later died of his injuries.
It is believed to be the 115th mass shooting so far this year in the US.
Two male suspects were arrested, one identified as 18-year-old Devon Erickson, who was a student at the school.
Erickson, 18, sat silently at a small table with his head bowed, hands shackled to his waist.
The other, who is under 18, is also understood to be a student at the school and appeared in a separate court hearing.
Douglas County District Judge Theresa Slade ordered the two suspects to remain held without bond pending their next court hearings on Friday, when formal charges are expected to be filed.
Nate's father Steve Holley told CNN it was the third time he had to pick his son up from school during shootings or threatened shootings.
"This community, in Colorado, we've been through so much recently," Mr Holley said.
"Enough is enough. We need to make a change and we need to do something, or else we're just going to continue failing our kids."
The school, which hosts kindergarten to year 12 students on one campus and has a total of 1850 students, was also put into lockdown weeks earlier when threats targeted nearby Columbine High School just days before the 20th anniversary of its mass shooting.