Damage in the garage after severe weather

Hello, we had in the Rhine-Main area on June 21 a violent storm with up to 60 l per square meter of rain! Not only the rain was running through the garage gate, it also ran through the leaky concrete ceiling and destroyed various objects among others furniture and a PC! Reason for the storage was that because of apartment renovation no space was to store the furniture elsewhere. Now the household furniture only took over the damage where the water ran through the gate. But the damage you If the rainwater has arisen from the ceiling, they do not want to take over! What now? Who pays for the damage? The garage is rented and belongs to a property association! Who can help or possibly even know court judgments or file number? Greetings