WINDER, Ga. (AP) — A shooter at a Georgia high school killed four people and injured at least nine 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.

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, outside of 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 episode is just the latest among dozens of school shootings across the U.S. in recent years, including especially deadly ones in Newtown, Connecticut, Parkland, Florida, and Uvalde, Texas. The killings in classrooms 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.

Prior to 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.

When she asked in the family group chat what was going on, he said there was a shooter at the school. Enoh’s younger sister, a junior at the school, said she had heard about the shooter and that everything was on lockdown.

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.

Few details were immediately available from authorities, who were dispatched shortly before 10:30 a.m. to respond to an “active shooting,” the sheriff’s office said in a statement.

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.

“I have directed all available state resources to respond to the incident at Apalachee High School and urge all Georgians to join my family in praying for the safety of those in our classrooms, both in Barrow County and across the state,” Georgia Gov. Brian Kemp said in a statement.

“We will continue to work with local, state, and federal partners as we gather information and further respond to this situation,” Kemp added.

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

The White House said President Joe Biden has been briefed about the shooting and the administration will coordinate with federal, state and local officials as it receives more information.

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, authorities said. More patrols of Atlanta schools would be done “for the rest of the day out of an abundance of caution,” 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.”