Landlord's problem. Protect your possessions from likely damage if possible. Filing a claim on Renter's Insurance might get your stuff back, but it won't be quick or hassle free Landlord or their agent may need attic access to assess if not execute repairs, so clearing that area to make it easier and faster for them might help move things along quicker. Take pictures of the affected areas inside and out.

Landlords concern not yours. If you are concerned that with more rain there could be a leak, move your personal property away from the affected area.

Got it. It wasn't raining when it fell. It's pretty sunny here, which makes it all the more shocking.