A shooter at a Georgia high school killed four people on Wednesday, authorities said, sending students scrambling for shelter in their classrooms — and eventually to the football stadium — as officers swarmed the campus and parents raced to find out if their children were safe.

At least nine people were injured and a suspect was in custody, authorities said. It was not immediately clear if the shooter was a student at Apalachee High School in Winder, Georgia, about an hour’s drive from Atlanta.

“What you see behind us is an evil thing,” Barrow County Sheriff Jud Smith said at a brief news conference outside the school. He declined to give details about the suspect. The Georgia Bureau of Investigation said four people were dead and at least nine injured.

The school shooting was just the latest among dozens across the U.S. in recent years, including especially deadly ones in Newtown, Connecticut, Parkland, Florida, and Uvalde, Texas. The classroom killings have set off fervent debates about gun control and frayed the nerves of parents whose children are growing up accustomed to active shooter drills in classrooms. But they have done little to move the needle on national gun laws.

Jacob King, a sophomore football player, said he had dozed off in his world history class after a morning practice when he heard about 10 gunshots.

King said he didn’t believe the shooting was real until he heard an officer yelling at someone to put down their gun. King said when his class was led out, he saw officers shielding what appeared to be an injured student.

Before Wednesday’s shooting, there had been 29 mass killings in the U.S. so far this year, according to a database maintained by The Associated Press and USA Today in partnership with Northeastern University. At least 127 people have died in those killings, which are defined as incidents in which four or more people die within a 24-hour period, not including the killer — the same definition used by the FBI.

Last year ended with 217 deaths from 42 mass killings in the U.S., making 2023 one of the deadliest years on record in the country.

Ashley Enoh was at home Wednesday morning when she got a text from her brother, who’s a senior at Apalachee High:

“Just so you know, I love you,” he texted her.

Sophomore Kaylee Abner was in geometry class when she heard gunshots. She and her classmates ducked behind their teacher’s desk, and then the teacher began flipping the desk in an attempt to barricade the classroom door, Abner said. A classmate beside her was praying and she held his hand while the students waited for police.

Layla Ferrell, a junior, was in a health class when the words “hard lockdown” appeared on a screen in the classroom and lights began flashing. Ferrell said she and her frightened classmates piled desks and chairs in front of the door to create a barricade.

Helicopter video from WSB-TV showed dozens of law enforcement and emergency vehicles surrounding the school in Barrow County, about 50 miles (80 kilometers) northeast of Atlanta.

When Erin Clark, 42, received a text from her son Ethan, a senior at the high school, that there was an active shooter, she rushed from her job at the Amazon warehouse to the school. The two texted “I love you,” and Clark said she prayed for her son as she drove to the high school.

With the main road blocked to the school, Clark parked and ran with other parents. Parents were then directed to the football field. Amid the chaos, Clark found Ethan sitting on the bleachers.

Clark said her son was writing an essay in class when he first heard the gunshots. Her son then worked with his classmates to barricade the door and hide.

“I’m so proud of him for doing that,” she said. “He was so brave.”

Students had only started the school year a little over a month ago.

“It makes me scared to send him back,” she said. “I don’t know what I’m going to do.”

Traffic going to the school was backed up for more than a mile as parents tried to get to their children there.

“It’s just outrageous that every day, in our country, in the United States of America, that parents have to send their parents to school worried about whether or not their child will come home alive,” Vice President Kamala Harris said during a campaign stop in New Hampshire.

In a message posted to social media, former President Donald Trump said: “These cherished children were taken from us far too soon by a sick and deranged monster.”

Georgia Gov. Brian Kemp said in a statement: “This is a day every parent dreads, and Georgians everywhere will hug their children tighter this evening because of this painful event.”

The FBI’s Atlanta office said its agents were at the school “coordinating with and supporting local law enforcement.”

Apalachee High School has about 1,900 students, according to records from Georgia education officials. It became Barrow County’s second largest public high school when it opened in 2000, according to the Barrow County School System. It’s named after the Apalachee River on the southern edge of Barrow County.

The shooting had reverberations in Atlanta, where patrols of schools in that city were beefed up, Atlanta Mayor Andre Dickens said.

In Winder, Abner said that when she goes home Wednesday night, she hopes to avoid thinking about those terrifying moments in her geometry class.

“I’ll probably not think about it, even though it happened,” she said. “Just think happy thoughts, don’t think about it anymore.”

Sophomore Shantal Sanvee, who was in a classroom near the gunshots, said “I saw, like, a whole lot of blood. And it was just, it was just horrible.”

“I don’t think I want to be here for like a long time now,” she added.

As an officer led the students towards the football stadium, freshman Michelle Moncada was in tears. People who she knew had been shot.

“I was just really, really nervous,” Moncada said.

The stadium was filled with tear-stricken students wondering whether their friends were okay. She saw one of her friends on the floor. A bullet had grazed him.

“It doesn’t feel real,” Moncada said.