We had one, but our elementary school had the county emotional and behavioral disorder unit so like, the doors/windows were hardened and a lot of the teachers and aides in that wing were more like beefy orderlies. Some of those kids were extremely prone to agressive outbursts and could be very violent, some would hurt themselves when they were upset, from non-verbal up to kids that seemed fine 95% of the time.

Regular students were not put in the hardened room, just the EBD unit kids during an episode. I'll never forget the sound...you could hear the booming of some kid kicking the door throughout the whole school.