I’m betting this school was retrofit with sprinklers. There were no sprinklers in the room of origin but the fire was contained to one room due to sprinklers in the adjacent corridor. [lafd.blogspot.com]
Sometimes in retrofits you’ll see this. Sprinklers are added only to the corridors for evacuation purposes. The principle concern in these situations is life safety. Of course Sprinklering the entire building is the best option but sometimes it just isn’t possible, financially or otherwise. In this case, I believe the fire sprinklers did their job. We’ll count this as save.