When Co-Workers/Friends get Rif’d?

For the second time this year, I received an e-mail from a current or former co-worker indicating their position had been eliminated. In the first case, the person was a good friend and I offered to be a reference in her next job search. In today's incident, the person was someone from another office who provided me with information. Although I did not know her, I still felt great sadness for her.

When this happens, what is the appropriate thing to do/say?