Remarkable and scary video of a trainer at Seaworld being attacked by an Orca.  From 2006, this was just released through a FOIA request.

It gets wild about 1:30 into the video. The Orca grabbed a trainer's foot. The man gets pulled under, then after a while the animal resurfaces and stays at the surface for a while, still holding the trainer's foot in its mouth. He keeps patting the animal, trying to calm it. Occasionally the Orca pulls him under again, as his foot is still in its mouth.  At one point, you notice that his foot is free yet he's still patting the animal.  Apparently, he cannot flee even though his foot is free, as the Orca will come after him.  So he continues to pat the animal while slowly pushing it toward the edge.  Just as he gets close enough, he releases the Orca then runs for his life to get out of the pool. 

The video is really quite horrifying but also fascinating.