Side view mirror fell off
 

I started the car up when I got off work. It had been sitting in the sun all day. The glass part of the mirror became unglued and fell off and broke..
Can I buy just the glass mirror and glue it on or do I have to replace the whole side view mirror.

There are some plastic replacements for the mirror only out there, don't buy one, the plastic deforms when you glue it in place and it's like looking into a fun house mirror at a carnival.

I see replacment mirror glasses on ebay but not sure if they're actually glass or plastic. I'd look into it to see if you can find a replacment.