It's a sad reality of life that tragedy often comes with absolutely no warning. One minute you're chilling on the beach and enjoying the sun, the next you're watching in horror as someone gets pulled into a riptide and nearly dies. Or maybe you're out at a show and the performer suddenly says something completely vile and the energy of the whole room instantly shifts.

Sometimes, these kinds of moments are even recorded on camera, like the moment this Russian circus bear started mauling its trainer.