A close friends's loss, don't know what to say

Millie1984

One of my best friends found out she was PG two weeks after me.  Since then we have gone shopping for maternity clothes together, we have been checking in on each other frequently, comparing symptoms, and basically we have been going through the entire pregnancy experience together.  

 She just texted me after going to her 16 week ultrasound that her baby did not have a heartbeat.  I feel terrible for her.  I texted her back that I am so sorry, and asked her if she wanted to talk, or if she would rather not.  She said she would call me tonight or tomorrow.  I honestly have no idea what to say to her when she calls.  I will let her take the lead on the conversation and see what she wants to talk about, but all in all I just feel so horrible for her and I want to be as supportive as possible.  Has anyone gone through anything like this before?  Any advice?