Water destroys garage wall

The garage roof is damaged. After every rain, streams of water penetrate into the wall. If this is not stopped, a crack may appear in the wall. This is the neighbor's garage. The neighbors have left. Not only the garage is destroyed, but also the roof of the house. I tried to repair the garage roof. I hope I managed to do this. I'll check it after the rain. But I can’t repair the roof of the house. It's sad to see houses that were abandoned by their owners being destroyed. Such houses are like children without parents.

And this is a video of the destroyed roof of a neighbor's house
Video: "Neighbors' roof damaged by hurricane"
https://rumble.com/v3yovmq-neighbors-roof-damaged-by-hurricane.html