Bizarre Mirror Problem

When I went to my car today, the mirror on the driver's door was missing. Just the glass mirror part, not the black housing/frame. There was no glass on the ground, so no one smashed it. I thought it was there when I parked the car. What could've happened? Can I get a new replacement mirror for it?
Comments
could be the glue became really hot and/or was worn out and the glass just came off the frame.
its quite easy to replace actually, you can use a sedan or a hatchback glass for it.
there is a hole on the bottom of the mirror. this is so you can stick a philips screw driver in it. the glass frame is held in place in a ball-joint like thingy, and there is a screw that tightens/clamps the frame to the ball-joint. look in the hole, find the screw and loosen it. then pop out the frame. it will take a little bit of force to do so.
then simply reverse the process for the new glass.
hope i didnt confuse you, like i just did myself.
you wont need any glue for the job though
anyways, the glass is the same as any ol' EF.