Kendrick Castillo, an 18-year-old student who was into engineering and just days away from his high school graduation, has been identified as the sole victim killed during Tuesday's shooting at STEM School Highlands Ranch in Colorado. Castillo died trying to stop one of the armed suspects from firing, allowing his classmates to escape. He was one of several students whose heroic actions prevented further carnage.

When a shooter walked into a classroom, three students including Castillo tried to take down the gunman, "CBS This Morning" reported. Student Nui Giasolli told "Today" that Castillo's actions gave the rest of her British Literature class time to get underneath their desks and then run across the room to flee safety. Castillo was killed and eight others were wounded in the shooting.

His father, John Castillo, told the Denver Post that his son "was the best kid in the world." He would have graduated on May 20.

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"I wish he had gone and hid," Castillo said, "but that's not his character. His character is about protecting people, helping people. I had a hard time accepting that."

Kendrick Castillo, 18, was killed in the shooting at STEM School Highlands Ranch. He's being called a "hero" for attempting to take down the gunman.

Fellow student Brendan Bialy said at a press conference Wednesday that he was in the room with Castillo and another student when they tackled the gunman.

"It was not a decision to go — when I saw Kendrick went up, I went up," Bialy said.

Bialy said he "couldn't be more thankful" that Kendrick did what he did.

CBS Denver reports Kendrick was interested in computer information technology and was supposed to compete in an event this weekend called "Rods and Robots." That event has been cancelled. Kendrick also had an internship set up.

Rachel Short told the Associated Press that Castillo was a funny and empathetic person who loved others and was a part-time employee at her manufacturing company, Bacara USA.

"To find he went down as a hero, I'm not surprised. That's exactly who Kendrick was," Short said.

Michael Schwartz, a friend of a victim injured in the shooting, told CBS News that seniors Josh Jones and Lucas Albertoni also helped Castillo stop the gunman. He said STEM senior Jack Gregory then dragged the shooter, now identified as 18-year-old Devon Erickson, out of the classroom.

"Jack came in and brought him into the hallway and disabled him, pinning him there and using force on him," Schwartz said.

Erickson was arrested. Authorities said Erickson and the other suspect, a female juvenile, are scheduled to appear in court Wednesday afternoon.

This shooting took place about eight miles from Columbine High School, where 12 students and a teacher died in a shooting 20 years ago last month.