Wicca buildings

I was on the top floor of a massive gothic building. There was something strange going on, and part of it started crumbling and collapsing - parts of the stained glass were dropping down the central stairway. I fled the building, running down the stairs, and out into the street.

I couldn't get to where I needed to be, people were in the way, but they needed to be warned of the collapsing building, but the bottom floor of the building was currently being occupied by a Witchcraft and Wicca convention.

I can't remember the rest!