Thanks for the info. I've only been in 1 of the 2 buildings, maybe I can get a last peak at the other before it comes down. Such a shame...I love those buildings! I went when it was raining a few weeks ago and ran into some fellow UrbExers; the place was all flooded and apocalyptic. I loved it.
Anyway, there are a few basic things to consider when throwing parties in abandoned / illegal spaces:
1. The police usually cannot enter, only the fire department. This means that emergency evac routes should be planned ahead and everyone needs to know what they are. Also, everyone should leave at once in the case of a bust - which is right when the fire dept. is about to come in. Going out early if you're about to be busted is a good way to get arrested / ticketed. Play it safe and go as a group.
2. Don't park anywhere near the site. Choose different locations and have people meet at a designated spot. Then, have another designated member walk them to the site.
3. Have several coordinators know what to do in case of emergencies and direct people as needed. At the same time, in the case of a bust / attention needed all the coordinators should make a weird noise than means everyone should shut up / calm down / etc. Something as simple as a hum. 200 people humming in unison is an incredibly calming feeling.
4. If money is being spent on props and the like and there is a bum rush to leave, have those coordinators grab as much of the props as possible when leaving.
Of course, this is dealing with 100+ people. Small gatherings probably don't need so much attention to detail...but I am a cautious character.