Authorities in Wisconsin say an armed 13-year-old boy carrying a backpack and a bag was stopped from entering an elementary school Thursday morning after being confronted by school staff and arrested hours later.

“We narrowly missed a tragedy,” Kenosha Police Chief Patrick D. Patton told reporters Thursday.

The 13-year-old, who previously attended Roosevelt Elementary School, tried to enter the building at about 9 a.m. local time, Patton said.

The suspect tried to enter through other doors to the school building but was unable to get in, Kenosha Unified School District Superintendent Jeffrey Weiss told reporters at a news conference. He then approached the front entrance and was buzzed into a vestibule area. Two school employees confronted the student, who became agitated and then ran away, Weiss said.

“I can’t stress … how heroic our office staff was,” Weiss said, adding, “They helped avert a disaster.”

Police later identified the teenage suspect, thanks to tips from the community.

“We can confirm that this was not just a suspicious individual, we believe this was actually a suspect armed with a firearm and there was no legitimate reason to enter the school,” Patton said at a news conference subsequent.

The police arrested the suspect shortly after 14:00 local time. During the earlier news conference, police released a video they said showed the suspect with a firearm and said the suspect had looked up school shootings online and made comments to fellow students in the weeks leading up to the incident.

Kenosha is located about 40 miles south of Milwaukee.