This is one of the most bizarre things I've seen happen on a baseball field. During Monday night's Cardinals-Rockies game, Michael Cuddyer fouled a ball off of the mask of Cardinals catcher Yadier Molina. The foul ball actually smashed Molina's mask so perfectly that a screw came loose from his mask and fell into the dirt. Check out the below screengrab, or fast forward to the 50 second mark of the video, to see the screw pop out.
The screw was eventually found, but not until the next inning started. What a bizarre situation.