Insurance Co obligations after 2 undiagnosed fires

[Nick G.]

I had an attic fire this April in a rental property (NJ) I own. The insurance company investigators determined a specific electrical cause (and were starting  to subbrogate) of the fire. Right at the completion of repairs, in August, there was another fire (perhaps electrical - there is stucco lath covering the house in contact) within a few feet of the first one at the attic eaves. Again this was investigated extensively by electrical engineers, fire investigators but no cause was found. Additionally it seems the cause of the April fire was misdiagnosed. So that's two fires with unknown causes, most likely the same cause. The insurance company settled for damages for the second fire and said "I can start repairs".

I do not want to proceed with repairs and risk (which seems quite possible) having another fire. Additionally the insurance company did not renew my policy.

Is the insurance company obligated to find and remedy the cause of a fire? Or to investigate further to find a cause? Just wondering what my options are.

I could sell "as-is" to a developer.