MADISON, Wis. (AP) — A 15-year-old student opened fire in a study hall at a small Christian school in Wisconsin, killing a teacher and a teenager and prompting a swarm of police officers to enter the school in response to a second-grader’s 911 call.

The police had previously stated that the emergency call came from a second grader. Madison Police Chief Shon Barnes announced the correction in a news conference Tuesday.

The girl also injured six other people in Monday’s shooting at Abundant Life Christian School, including two students who were in critical condition, Barnes said. A teacher and three students were taken to a hospital with less serious injuries, but two of them were later released.

“Every child, every person in this building is a victim and will forever remain a victim. … We need to figure out and try to piece together what exactly happened,” Barnes said.

Police said the shooter, identified as Natalie Rupnow, was found with a self-inflicted gunshot wound when officers arrived. She died on the way to the hospital, police said. Barnes declined to provide further details about the shooter, partly out of respect for the family.

Abundant Life is a nondenominational Christian school – pre-K through high school – with approximately 420 students in Madison, the state capital.

Barbara Wiers, the school’s director of elementary and school relations, said when they practice safety routines, principals always announce that it is a drill. That didn’t happen on Monday, just a week before the Christmas holidays.

“When they heard ‘Lockdown, Lockdown,’ they knew it was real,” she said.

Wiers said the school does not have metal detectors but uses other security measures, including cameras.

A motive for the shooting was not immediately known, nor was it clear whether the victims were targeted, Barnes said.

“I don’t know why, and I feel like if we knew why, we could prevent these things,” he told reporters.

Barnes said police spoke with the shooter’s father and other cooperating family members and searched the shooter’s home.

“He lost someone too,” Barnes said of the shooter’s father. “That’s why we’re not going to rush the information. We will take our time and make sure we do our due diligence.”

The first emergency call reporting an active shooter came in shortly before 11 a.m. Monday. First responders who were in training just three miles away rushed to the school for a real emergency, Barnes said. They arrived three minutes after the first call.

Investigators believe the shooter used a 9mm handgun, a law enforcement official told the Associated Press. The official spoke on condition of anonymity because he was not authorized to discuss the ongoing investigation.

Police cordoned off streets around the school and federal officers were on scene to assist local law enforcement. The police did not fire any shots.

Children and families were reunited at a health clinic about a mile from the school. Parents hugged their children to their chests while others squeezed hands and shoulders as they walked side by side.

Abundant Life asked for prayers in a short Facebook post. Wiers said they are still deciding whether to resume classes this week.

Bethany Highman, the mother of a student, rushed to school and found out via FaceTime that her daughter was OK.

“Once it happens, your world stops for a minute. Nothing else matters,” Highman said. “There is no one near you. You just run to the door and try to do whatever you can as a parent to be with your kids.”

In a statement, President Joe Biden referenced the tragedy as he called on Congress to pass universal background checks, a national red flag law and certain gun restrictions.

“We can never accept senseless violence that traumatizes children and their families and tears entire communities apart,” Biden said. He spoke with Wisconsin Gov. Tony Evers and Madison Mayor Satya Rhodes-Conway and offered his support.

Evers said it was “unthinkable” that a child or teacher would go to school and never return home.

The school shooting was the latest of dozens in recent years across the U.S., including particularly deadly ones in Newtown, Connecticut; Parkland, Fla.; and Uvalde, Texas.

The shootings have sparked heated debates about gun control and frayed the nerves of parents whose children are growing up accustomed to active shooter drills in their classrooms. But school shootings have done little to change the nation’s gun laws.

Guns were the leading cause of death among children in 2020 and 2021, according to KFF, a nonprofit organization that addresses health care issues.

Rhodes-Conway said the country needs to do more to prevent gun violence.

“I hoped that day would never come to Madison,” she said.

Contributor: Alanna Durkin Richer, Ed White, Hallie Golden, Morry Gash and Josh Funk