A public service announcement video shared by nonprofit group Sandy Hook Promise has stirred up significant controversy for its depiction of school children bleeding and screaming for their lives during an active school shooting.

The video begins as a satire of “back-to-school” commercials with young children showing off their new school supplies. After a few frames, screams can be heard in the background as the children promoting their new gear start to use school supplies as defensive weapons. Children jump through broken windows and wait, terrified, in locked classrooms and bathroom stalls.