A second grader called 911 to report the deadly mass shooting at Abundant Life Christian School in Madison, Wisconsin, police said.

“I’m going to let that soak in for a minute,” Madison Police Chief Shon Barnes said during a press briefing while providing a timeline on the Monday morning shooting. “A second grade student called 911 at 10:57 a.m. to report a shooting at school.”

A student and teacher were killed in the shooting, police said. Two students were hospitalized in critical condition, while three students and a teacher also suffered non-life-threatening injuries, police said. The suspected shooter, a teenager who was a student at the school, died of an apparent self-inflicted gunshot wound, police said.

The shooting happened inside a classroom during a study hall of students from multiple grades, Barnes said.

“To me, it makes my heart skip a beat, to think about that,” Barnes said of the young student calling 911 to report the shooting. “We teach our kids, if something’s wrong, call what, 911. And so the child was able to do that.”

Barnes said the 911 dispatch communicators are trained to talk to children.

Students in kindergarten through 12th grade attend the small Christian school.

Nora Gottschalk, an elementary school student at Abundant Life Christian School, told Chicago ABC station WLS that she was in the hallway when she heard the gunfire.

“I was changing from my shoes to my boots to go to lunch, ’cause I have recess after,” the second grader told the station. “But then I heard the shooting. And screams.”

Nora was still barefoot in the hours after the shooting.

“We went to the church right next to my school, and everyone was panicking still, because a lot of police were there,” she told WLS.

Her dad, Karl Gottschalk, said he was on the road for work when he saw first responders.

“I saw the cops driving by, then I got the text from the school,” he told WLS. “That really hit me hard as I’m driving down the road, seeing ambulances.”

Police identified the suspected shooter as 15-year-old Natalie Rupnow, who went by Samantha.

Police have not yet suggested any motive for the attack nor said whether they believe the victims were specifically targeted.

“This has been a rough day for our city. This has been a sad day,” Barnes said. “This is going to be a day that will be etched in the collective minds and memories of all those from Madison.”