This exact thing happened to us 8 months ago. Literally the day that we closed on the house I found water coming in to kitchen. I called our home warranty company, they sent out a plumber to investigate, then told us that it wasnt covered. The plumber that was there referred us to these guys:

Mike Bartholomew
Independent Restoration Professionals
CA License B 942053
858.774.0772 cell

and suggested we work with our insurance company. Mike helped us work with the insurance company, walked us through the restoration process and what to expect. I cant say enough good things about what an excellent help Mike and his team were through the process. We got a whole new kitchen out of the ordeal.