I own a 1st floor condo in Long Beach. We have been dealing with a water leak coming from the upstairs neighbor's master bathroom.

My insurance denied the claim because "it appears to be a long term issue and not a sudden occurrence." Today, the upstairs neighbor's Liability Adjuster came out and is denying the claim because "it appears to be a hidden issue that nobody was aware of and couldn't have stopped, therefore it's nobodies fault." She said to me and to the owner upstairs that we should both pay for the repairs to our respective units.

The HOA has been out and they determined that the cause of the leak is in the upstairs bathroom (likely a bad shower pan) and they are not responsible for the damage since it was the upstairs' unit's bathroom.

What are my rights now? I am facing a $10,000 repair job, once the upstairs unit finally repairs the cause of the water intrusion. How do I get these repairs done without going broke?

If the leak originated in the neighboring unit, then you need to present the claim to your neighbor's homeowner insurance. The "sudden escape of water" rule normally applies only to property insurance. In this instance, your neighbor may have a legal nuisance or trespass originating in his unit to the extent your neighbor's water invaded your unit. Your claim should not be subject to the property coverage exclusions, because it is a liability claim.

Whether or not any insurance covers the problem is a separate question from whether or not somebody is liable for the problem. You, your association, and your neighbor would benefit from a lawyer sorting all this out, followed by a mediation in which reasonable neighbors work together for a non-lawsuit solution (in California, yes, it is still socially acceptable to NOT sue your neighbor!).