Who is responsible for condo water damage downstairs?

I live in a second-floor condo and I have no home insurance, A leaking pipe inside the wall caused water damage to downstairs unit. The pipe was connected to my water heater, but it was hidden in the insulation in the deadspace between the two units, therefore there is no negligence. Since my property manager thinks I should be responsible for the damage, he sent plumber and restoration company for repair. I have spent over $5000 to fix the leak and dry out my neighbor's wall and carpet, but there is still more to do for the restoration of his unit. Later I learned that I might not have to be responsible for the damage downstairs. Both my neighbor and HOA have filed their insurance claims. Since I have no insurance, I have to represent myself, but I have not been contacted by either of the insurance companies yet. I am worried that their insurance companies will not pay and I have to pay all the repair cost for my neighbor. If they pay, from whom shall I get reimbursed?