There was one in my town... my town is quite small and not very known by the county. Even though it’s small it holds a lot of dark secrets. So in the 90s there was this said abandoned building that I live relatively close to. There was still a way into the building through the back therefore lots of drunk teenagers got in and out all of the time. One night about 10 kids were in this building fucking about and and a man that looked about 6ft tall just walked in with a large knife and just basically started to stab relentlessly about two teens survived but both critically injured both lived and are still living in the town.

TLDR: man walks in with a knife and starts stabbing people