Damaged Ceiling

This is a NSW question for pre-’74 building.

We have carport on street level underneath the units and behind the carport are the storerooms. The storeroom belongs to each unit and the owner holds the key to their respective storeroom. 

1. Recently one of the owners in our unit block complained that they cannot use their store room located on street level because the ceiling was damaged and flaking. They hold the key to their storeroom. They have been living there for over 5 years and the damage was there prior to them purchasing the unit. In all these years they never reported the issue to the Strata manager or the committee. It is possible that the water leaked through bathroom floor from the unit above causing the damage. Who is responsible for the cost of repair? Owner or Owners Corporation?
2. Another owner reported a crack in their living room ceiling. They have been living there for over 7 years. Once again the issue was never reported to the Strata manager or the committee. Who is responsible for the cost of repair? Owner or Owners Corporation? 

Thanks