One of my very first batches was a high gravity Saison. My wife and I just moved into our last apartment at the time. We were both at work and when I came home I found the lid of my bucket on the floor next to the fermentor, krausen painted up both walls (it was in the corner) and on the ceiling. I'm surprised the airlock didn't come through the floor of our upstairs neighbors' apartment lol. We did not get our security deposit back...
Since then I have used a blowoff tube for every batch. FYI, what happened in my situation was that a little tiny hop particle clogged one of the orifices on the bottom of the airlock. It doesnt take much to cause a HUGE mess. Cheers!