Blamed for something I didn't do.?

I'm in college, and apparently my buddy down the hall decided to smoke weed in his dorm room. I didn't know and i didn't even know he had weed in his room. The hallway smelled like weed, so i wasn't sure if it just go in his room or he smoked inside of it. But later that night when we were playing ps3, the campus security came knocking on my friends door while i was in there. They threatened to arrest everyone who was in the room. They raided my friends room, and found the weed. They arrested him, and let the rest of us go to our rooms. A week later i get a email saying i have a hearing, by the college dean board or whatever. So what can i say to them? I think its crap that i have to deal with this when i never did anything.