Flying Discs

So I work in a large photographic lab.  One day I was standing in the hallway outside the lab, for about a minute, when I heard crashing inside.  I walked back inside and all the CD's and their cases that were stacked on a shelf on the wall on the opposite side of the lab had flown off and landed 20 feet away.  Eveyone else in the lab were standing fifteen feet away looking at the CD's.  No one had been close to them, and no one had touched them for several days previous.

We're not sure if it was the vibration of the wall from another floor.  However, we have smelt random pipe tobacco, heard footsteps when no one outside, foot prints on chairs when we come in early in the morning.  Of course, the pipe tobacco could be from the air intake, the footsteps echos from across the floor...

I'll let you decide.