Legal Question in Real Estate Law in California

You should not have to figure out who is responsible or whose insurance will reimburse your losses. Speak with both the building owner or manager and the neighbor. Find out who their insurers are. Find out which is assuming responsibility (if and when they decide) and arrange for an inspection by an adjuster.

You are going to have to pursue the party responsible for the fire. That could be your neighbor, or it could even be the landlord. If your neighbor had insurance, they may have a duty to defend and indemnify him for any losses you sustained, if you could prove the fire was his fault. Many tenants do not have renter's insurance, and even if they do, some types of damage may be excluded from coverage under the policy. If your neighbor did not carry insurance, he may not have much property to attach if you get a judgment. That is why you should have had insurance in the first place.