HIGHLANDS RANCH — Two students attending the STEM School Highlands Ranch brought at least one handgun into the school Tuesday afternoon and turned the weapon on their classmates, killing one 18-year-old male and injuring eight other students.

It was the fourth school shooting in Colorado since the Columbine High School massacre 20 years ago.

The male suspects, one adult and one juvenile, were taken into custody by Douglas County sheriff’s deputies within two minutes of a 1:53 p.m. report of shots fired, Sheriff Tony Spurlock said.

Sheriff’s officials late Tuesday identified the adult suspect as Devon Erickson, 18. The names of the victims and the juvenile suspect were not released.

“We know that two individuals walked into the STEM School, got deep inside the school and engaged students in two separate locations,” Spurlock said. “There were a number of students that were shot and injured.”

At least four of the victims been treated and released from hospitals by Tuesday evening.

STEM School Highlands Ranch will be closed the rest of the week, Douglas County School District officials announced Tuesday night.

When reports of the shooting surfaced, worried parents raced to the school to search for their children. They were redirected to a nearby recreation center to wait to be reunited.

The shooting renewed calls for more gun control and tighter school security as a community, fatigued from violence inside schools, reeled at the news. Politicians from the White House to the Denver mayor’s office sent condolences, and Denver’s professional sports teams who had games Tuesday night held a moment of silence.

The STEM School, which has 1,850 students in kindergarten through 12th grade, was put on lockdown until police cleared the school room by room. Other Highlands Ranch schools were placed on lockout. The school has private security but does not have a school resource officer.

The suspects had at least one handgun, but Spurlock said he did not know how many or what types of other weapons they used.

Undersheriff Holly Nicholson-Kluth told reporters at a news conference that the first deputies to arrive found some sort of struggle and then took the suspects into custody. Spurlock also said the deputies struggled with the suspects.

The suspects were not hurt, Spurlock said.

The two male students accused in the shooting were not on any type of law enforcement watch list, the sheriff said. He said he would not talk about any possible motives or methods they used in the attack.

RELATED: How to talk to children after STEM School shooting in Highlands Ranch

The FBI is assisting in the investigation, and the Colorado State Patrol also was called to help, the sheriff said. The 18th Judicial District Attorney’s Office was applying for search warrants for the suspects’ homes and cars.

Police could be seen outside the Erickson family’s home on Mountain Maple Avenue in Highlands Ranch on Tuesday night. The house itself was cordoned off with police tape and investigators could be seen inside.

Authorities eventually towed a white Honda sedan from the property. A pentagram with the numbers “666” could be seen on the hood of the car, as well as the phrase “(expletive) society” on the passenger-side door.

“It was so scary”

Diego Palmer, 13, said he was in study hall in the cafeteria when several students bolted through the door yelling, “School shooting! School shooting! Get out now!”

He wasn’t sure if it was real but didn’t take any chances, running outside with other students to a nearby brewery where his mother picked him up.

“It was so scary,” he said.

People headed toward Highlands Ranch Rec Center, where parents have been told to stage. Helicopter overhead. @denverpost pic.twitter.com/ebOUtHgzkq — Elise Schmelzer (@EliseSchmelzer) May 7, 2019

The injured were taken to area hospitals. Littleton Adventist Hospital said it received five patients, and three were treated and released. SkyRidge Medical Center confirmed it had two patients, who did not have life-threatening injuries, according to a spokeswoman. Children’s Hospital Colorado had another patient, who was treated and released.

Parents first went to the school and then were directed to Northridge Recreation Center, where they were organized by alphabet to be reunited with their children. At the center, parents focused on their cell phones as they waited to hear from their children or to catch updates from law enforcement and the media.

Preeti Grover received three frightening texts from her 12-year-old son Vivaan Kalura at 1:59 p.m.

“THERE IS A SHOOTING AT SHOOL.”

“IM FING SCARED.”

“TWO KIDS HAVE BEEN SHOT.”

At first she thought he was talking about another school. But the messages continued.

“IM CRYING. I SWEAR TO GOD THIS IS NO JOKE.”

Vivaan had been inside his math classroom when he heard a loud thud. And then two gunshots, in what seemed like the next classroom over.

His teacher huddled the students under tables in the back of the classroom. The teacher told them to stay calm, he said.

Soon police escorted the children from the classrooms. Vivaan said they were told to keep their hands on their heads. They walked past pools of blood in the hallway, he said.

Grover raced to the school — her 8-year-old son was also there. The 8 minutes were an eternity, she said.

Waiting for their children

She then joined the hundreds of parents who packed into the Northridge Recreation Center on Tuesday afternoon to wait for their children. They typed text messages on their phones, made phone calls and refreshed news websites looking for details. Some cried into the shoulders of friends. Others cried alone.

Glass-walled racquetball courts served as playrooms for the kids too young to be in school who waited with their parents.

A state trooper slowly released parents to meet their children in separate rooms. The youngest — who were 5 years old — were released first.

“I’m just trying not to vomit or cry,” one mother said, who asked that her name not be used. Her son had been able to text her, but she was waiting to see him again.

Some parents went to the school first.

Matt Murphy already was on his way to pick up his daughter, 11, and son, 9, from the school when his wife called to tell him “something was going on.” When he pulled up, there was chaos rather than the normal line of cars waiting for students to be released.

He talked to his daughter Madelyn, and she told him that she was OK.

“It’s just too bad that we have to worry about this,” Murphy said. “I know my kids and their friends are OK, but I know there are people who are not.”

Brian Jones, whose son Asher is in the second grade at STEM, dashed to the campus after his boss told him about a shooting. He arrived to see heavily armed sheriff’s deputies headed inside.

About an hour later, Jones saw Asher walk out of a classroom and he yelled his son’s name to let the boy know his father was there.

“It’s nerve-wracking,” Jones said. “There were lots of parents and lots of kids crying.”

Outside the rec center, a stream of parents walked with their children back to cars that had been haphazardly parked on curbs and grass along South Broadway. Mothers cried as they held their children. The students told their parents what they saw and heard — how a quiet Tuesday turned into the scariest moments of their lives. One elementary school student held his sweatshirt over his head as he walked past the news cameras outside.

Vivaan isn’t sure if he wants to go back to school Wednesday. He thinks — but isn’t sure — all of his friends were OK.

“You always see other people when it’s happening somewhere else,” Grover said. “I never thought it would be us.”