Just a few miles from Columbine High School, gunfire echoed through the hallways of yet another Colorado school.

This time, it was the STEM School Highlands Ranch near Denver.

Authorities believe two students, a male and a female, used a pair of handguns to open fire in two classrooms Tuesday afternoon.

An 18-year-old student just days away from graduation was killed, Douglas County Sheriff Tony Spurlock said Wednesday. Eight other students were shot but survived.

The parents of Kendrick Castillo confirm their son was the student killed. A witness in the classroom told CNN that Castillo was shot while rushing a shooter and credited him with saving several lives.

Students at the STEM school hug Tuesday after two suspects opened fire inside the school.
Students at the STEM school hug Tuesday after two suspects opened fire inside the school.

The grieving community had just marked the 20th anniversary of the Columbine High School shooting in nearby Littleton that left 12 students and a teacher dead.

But the Columbine shooting changed the way police respond to active shootings. In 1999, it took 47 minutes after the gunfire erupted for SWAT teams to enter. On Tuesday, authorities were inside the STEM school within a few minutes after getting the first calls.

“I have to believe that the quick response of the officers that got inside that school helped save lives,” the sheriff said.

But the tragedy dealt another traumatic blow to a community too familiar with mass shootings.

“If you had suggested … that in 20 years, in 20 miles, we would have dealt with Columbine, Aurora theater, Arapahoe High School, the shooting of Zack Parrish and four other deputies, we’d have thought you mad,” district attorney George Brauchler said Wednesday.

“Yet here we are again.”

A private guard was one of the first to confront a shooter

The STEM school doesn’t have a school resource officer, but it did have a private security guard, Spurlock said.

And that guard was among the first to confront one of the suspects, said Grant Whitus, chief operating officer of BOSS High Level Protection.

Whitus — the first SWAT officer to enter Columbine 20 years ago — declined to identify the guard but said he was “instrumental” in stopping the attack.

He said the guard drew his gun, took the suspect into custody and turned the suspect over to sheriff’s deputies.

Had the guard not been on site, “countless lives would have been lost,” Whitus said.

But the guard still feels bad that he couldn’t stop the entire attack.

“He’s a very good guy,” Whitus said. “He’s wishing he could have done more.”

Students also tried to stop the attack

As more details emerge, so might more tales of heroism, the sheriff said.

One senior at the STEM school — Brendan Bialy — told his father that the shooting started after the two attackers entered a classroom, and one pulled a gun from a guitar case, The New York Times reported.

Brendan and two friends tried to tried to tackle one of the attackers, Brendan’s father Brad Bialy told the Times. But one of the boys was shot in the chest. Other students put pressure on the wound.

The motive remains a mystery

The Douglas County Sheriff’s Office identified one of the suspects as 18-year-old Devon Erickson. Authorities identified the second suspect as a female juvenile.

But investigators are “still working towards a motive,” Spurlock said.

Authorities searched a home Tuesday night, but officials would not confirm if one of the shooters lives at the home.

The sheriff said the two suspects didn’t appear to be on law enforcement’s radar.

Just a few weeks ago, Douglas County Schools feared another attack and shut down schools April 17.

Police scrambled to find an armed teen they said was infatuated with the Columbine massacre. The 18-year-old Florida woman made threats before traveling to Colorado, authorities said.

After news broke of the teen’s threats, the young woman’s body was found with a self-inflicted shotgun wound, officials said.

‘You never think this would be the new reality’

Fernando Montoya’s 17-year-old son was shot three times, but he survived and was released from the hospital.

“Thank God he is fine,” Montoya told CNN affiliate KMGH. “Even though he got shot, he’s OK. He’s going to walk out on his feet.”

But the teen is still grappling with the fact that such violence could happen at this school.

“It’s hard to believe that someone in the classroom is going to have a weapon and is just going to open fire like nothing,” Montoya told KMGH.

Parents waited for their children Tuesday a recreation center in Highlands Ranch.
Parents waited for their children Tuesday a recreation center in Highlands Ranch.

The mother of another student said she got a horrifying call from her daughter:

“‘Mommy, there’s a gun (being) shot at my school,'” the mother recalled to CNN affiliate KDVR.

“(With) everything at Columbine, you never think this would be the reality of this situation.”

‘Our STEM family is hurting’

More than 1,850 students attend the STEM school, which includes grades K-12.

“STEM” stands for science, technology, engineering and math. The STEM School Highlands Ranch is a “free, public charter school,” according to its website.

“Our STEM family is hurting tonight,” Douglas County School Superintendent Thomas S. Tucker said in a letter to families Tuesday. “Supporting one another in the coming days, weeks and months is critical.”

The school will be closed the rest of the week.