Maybe a dumb question, but why would this warrant an evacuation? I get that it's contraband, but it's drugs, not a weapon. Unless they thought since one disallowed thing made it's way in that there could be other stuff (weapons) as well?
Edit: or maybe they thought it could be anthrax at first, which makes much more sense as to why they would evacuate
Is this one of those "toxic relationships" I've been hearing so much about lately?