A 16-year-old boy was arrested Friday after he allegedly stabbed a 15-year-old boy to death at a Minnesota high school.

Harding High School in St. Paul went into lockdown shortly before noon Friday, and students were kept in their classrooms until nearly 2 p.m., KARE reported.

Classes for the remainder of the day and on Monday were canceled, along with all evening and weekend activities.

According to the Minneapolis Star Tribune, responding officers found school staff administering first aid to the victim. He was taken to Regions Hospital, where he died.

“My plea to our entire community right now is that we are not okay. Our kids are not okay,” St. Paul School Superintendent Joe Gothard said in a videotaped message. “As evident by this event, has also been marked by other incidents throughout our city, whether it’s in our schools or in our community that tells us that our kids are hurting, our staff are struggling to support them and know what to do. This is a time for us once again to come together, to work together, to make sure that we’re supporting everyone in coming through these times of great grief and great tragedy as we move forward together.”

St. Paul Police Public Information Officer Sgt. Mike Ernster said investigators were still trying to determine the events that led up to the fatal stabbing. He said he believes the weapon was a fixed blade knife and said investigators were aware of a “rumor of a social media video” of the stabbing but had no other information.

“We’re still working through the facts ourselves and interviewing witnesses to this incident,” he said.

For the latest true crime and justice news, subscribe to the ‘Crime Stories with Nancy Grace’ podcast.

[Featured image: Harding High School/Google Maps]