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 trying to protect his classmates, a witness said.
Eight other students were shot but survived.
Now, a community far too familiar with mass shootings is oscillating between grief and gratitude.
A student lost his life protecting classmates
Kendrick Ray Castillo was a kind, hilarious jokester who was always ready to help his classmates, student Tuscany “Nui” Giasolli said.
“Kendrick was such a nice kid. If you needed something, he would be there for you,” Nui told CNN on Wednesday.
That proved true even in the young man’s final moments.
Castillo and Nui were analyzing comedy in English class and watching “The Princess Bride.” That’s when one of the shooters walked in.
Nui said the suspect talked to the teacher, then walked around the room.
“Next thing I know, he’s pulling out a gun,” Nui said.
She said the gunman told everyone not to move. “And that’s when the shooting started.”
But Castillo wouldn’t stay still. He lunged at the shooter, giving classmates enough time to hide, Nui said.
Three other students also tackled the gunman and tried to subdue him while the rest of the class fled the room.
Nui’s mother, Nyki Giasolli, said if not for the heroism of her daughter’s classmates, “I wouldn’t have my baby today.”
“All these kids are alive because of (Castillo’s) sacrifice and the bravery of all the boys to neutralize the threat,” Giasolli said.
How the Columbine shooting nearby changed everything
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,” Douglas County Sheriff Tony Spurlock said.
But the tragedy dealt another traumatic blow to a community that’s endured a rash of 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.”
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 on Tuesday, 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.
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.