SANTA CLARITA, Calif. — Two students were killed and three other teens were wounded in a shooting at Saugus High School in Santa Clarita on Thursday morning, authorities said.

Shots rang out just after 7:30 a.m. when students at the school at were scheduled to be in their first-period class. Los Angeles County Sheriff Alex Villanueva said the department got a call about the gunfire at 7:38 a.m. Two minutes later, he said, sheriff’s deputies arrived at the school and found six students, including the suspected shooter, with gunshot wounds.

Paramedics swarmed the campus, treating the wounded, while deputies, the SWAT team and federal officials combed nearby neighborhoods searching for a 16-year-old boy they thought had fled the campus after the shooting. After roughly an hourlong search, authorities said the suspect had been apprehended.

Authorities did not release the teen’s name, but said Thursday is his 16th birthday. He is being treated at a hospital for a gunshot wound to the head, Los Angeles sheriff’s Capt. Kent Wegener said.

Wegener said the teen was standing in the quad when he pulled a .45 caliber handgun from his backpack and opened fire at other students, before turning the gun on himself.

Four people from the school were transported to Henry Mayo Newhall Hospital for treatment. Two students, a 16-year-old girl and a 14-year-old boy, died there. A 15-year-old girl, a 14-year-old girl and a 14-year-old boy are being treated. Their conditions were not immediately known.

The scene at the high school was chaotic, with teenagers walking in a line behind armed law enforcement officials with their arms raised in the air immediately after the shooting. Many of the injured were being treated in a grassy area on the campus before being placed on gurneys and transported to ambulances in the school’s parking lot. At least one person was found wounded in the school’s choir room, authorities said.

Some students remained locked in classrooms for more than an hour as authorities searched for the shooter. Eventually, they were led off the campus by deputies. Some were in tears. As they walked, one student asked aloud a question on the minds of many others across the state: “What kind of a world is this?”

“You hear about it all the time, and it’s finally (happened) at home,” parent Tony Barrett said. “You always see it on the news and don’t think it’ll happen to you.”

Andrei Mojica, 17, was in his AP Government class going over a worksheet when his teacher went outside and saw people running. Nobody in class panicked until somebody opened the door and said there was a shooter on campus. His heart sank.

In an instant, the class of about 30 was up and barricading the doors with desks and tables. They’d practiced this before, but “there was just something different about it from a simple drill to real life,” he said.

The class sat in silence and had a fire extinguisher they were prepared to use as a weapon if anyone came into the classroom. They didn’t hear any gunshots.

“We had no clue whether the shooter was on the opposite side of campus or right outside our door,” he said. “That fear made it feel like we were waiting in silence forever.”

All schools in the William S. Hart Union High School District were briefly locked down as authorities searched for the shooter. Deputies had been centering much of their focus on the brushy area behind the high school adjacent to a creek where authorities thought the shooter might have been hiding. Law enforcement officials were also searching the backyards of homes along Sycamore Creek Drive.

Inside Central Park, just down the street from the school, a stream of parents — some sobbing, others glued to their phones — gathered in a circle. They had been directed there by law enforcement to be reunited with their children.

A helicopter thumping overhead drowned our their cries and ambulances blared in the distance. It was, by now, a familiar scene — three weeks ago officials and frantic Santa Clarita residents had gathered in this same park for a news conference during the Tick Fire.

Nearby, a sheriff’s deputy gripping a machine gun asked a frantic woman if she was a parent.

“Yes!” she said, sobbing. He pointed her away from the yellow tape, toward a group of parents and teens, standing in a clump.

One of the parents wrapped his arm over the shoulder of a teenage boy dressed in a gray “SAUGUS” sweatshirt. The boy was hyperventilating and counting his breaths aloud.

“One, two, three,” he said. “One, two, three.”

“It’s over, son,” the man said. “It’s over.”

Michael Harrison, 26, said he first became aware of the shooting when his younger sister, a 17-year-old senior, texted him: “there is a shooter, call 911.”

“I can’t even describe it, man,” Harrison said with a panicked laugh. “Imagine getting that text.”

On Thursday morning, Harrison and Kimberly Simpson, 30, were standing next to one another across the street from Saugus High’s main entrance, where dozens of emergency vehicles and sheriff’s deputies in tactical gear had flooded the street, some parking in private driveways. One deputy could be heard telling a parent that law enforcement was conducting a “systematic search” to clear all the classrooms.

Simpson’s 15-year-old daughter, a junior, was in class Thursday morning when a teacher ordered students to do what they had drilled for, referring to lockdown procedures after a shooting.

“She’s freaked out. She’s scared,” Simpson said. “I don’t know if she’s going to want to go back.”

Anthony Breznican, 43, had just dropped off his daughter and son at school when his wife alerted him to news of a shooter at the high school. Breznican sprinted back to the North Park Elementary, where parents began piling into the lobby as details emerged.

“You’ve got kids in little pilgrim outfits planning to do their Thanksgiving pageant today walking out in tears,” Breznican said.

His 10-year-old daughter, a fifth grader, burst into tears as she told him that a kid had hurt people at Saugus High School. Breznican said that several of the students gathered at his house, where they’ve been distracted by the television in an attempt to return to some semblance of normalcy.

Although residents say Santa Clarita is an idyllic place, he said that it has not been untouched by violence. Some members of the community were killed in the 2017 Las Vegas shooting. Others had friends affected by last year’s Thousand Oaks shooting.

“Santa Clarita had this threat of this looming over its head for a long time. My daughter started kindergarten in 2014, and on the first day, there was a parking lot full of sheriff’s deputies because a kid posted to Instagram that he was going to shoot up the school,” Breznican said. “You’d be crazy to think that something like that couldn’t happen here.”

The shooting came two months after six students at the high school were detained on felony criminal charges after authorities were alerted to threats the teenagers had made online. A Hart Union staff member discovered the social media posts “regarding committing acts of school violence” and alerted authorities, according to the Sheriff’s Department.

Detectives quickly determined who had made the posts, according to the agency. It’s unclear whether those threats were connected to Thursday’s shooting.

Former U.S. Rep. Katie Hill stood in her backyard in Saugus as helicopters circled overheard. Hill graduated from Saugus High School in 2004, when active shooter drills were never discussed. Thursday morning, her father sent her a text alerting her to the news.

“I’m absolutely horrified that it’s happening at my school,” she said.

The community is a close-knit one. Hill said that several of her staffers are graduates of the high school, and currently know parents with students at the school.

“This is what we’ve all been afraid of,” she said.