Have you ever been fired before, or one of your colleagues?

What were the main reasons for him being fired?

The objective of this question is to get a list/description of other peoples experiences too see if we can come up with a theme of why people are let go.

For those that work for consulting companies, I would guess one of the main reasons would be a developer is just too slow pumping out code.

So my guesses would be:

 1) attitude 
 2) too slow

Please specify if you are saying something from experience or just guessing.