Seller backing out

[Josh Kliethermes]

I have closing scheduled one week from today, and today the seller is saying they are backing out of the deal.  I have a signed purchase agreement with the seller and have proof of being able to go through with the purchase on my end (financing good to go, title company set up, etc.).  

What are my courses of action here to get this deal to go through? Is suing for specific performance the way to go?