Emergency crews rushed to Franklin Regional High School in Murrysville, Pennsylvania, on April 9 following reports of a knife attack. Dan Stevens of Westmoreland County Emergency Management Services confirmed that one security guard and 19 students were injured in the attack, four seriously. Those with injuries were taken to three local hospitals.

One person was reported to be in custody after the attack.

This footage was taken from the scene shortly after the attack and shows an interview with a student, whose friends were hurt in the stabbing. Credit: Instagram/Brandon Hudson