Legal Question in Insurance Law in California

It depends on what caused the fire.

Mr. McCormick is correct. And since it may not be clear what caused the fire - and there may not have been only one cause - the best procedure is to file a claim with your insurance company and also make a demand on the contractor. Your own insurance company may even do the latter part on its own behalf (called subrogation), so you should check with them first. Also, you should understand that your claim is, technically, against the contractor. What happens between the contractor and his/her insurance company is between them.