Picked up my BH Shockwave off my shelf where my Prime toys, Cybertron Voyagers/Ultras and Classics Soundwave+cassettes are for a play.

Put him back and suddenly the bolts under the shelf turned, making the shelf crash onto the one below, which, naturally, to my luck, is where my Lego Star Wars stuff is, such as my B-Wing and MTT. (Multi Troop Transport)

I managed to swiftly remove the MTT just in time, but everything, including all the lego minifigs and Transformers fell to the floor, already crushed by the shelf.

My Yugioh deck, which I'd just also sleeved was scattered everywhere and I think there's still some floating around somewhere.

Took a good 20 minutes to clean it all up and put them back in place, but I now have an incessant fear that it'll happen again.