The sewer water came out of the toilet on the first level and destroyed the carpet, drywall, etc.

If the area were destroyed by a hurricane, businesses shut down, tourism industry declined etc., would it even be worth rebuilding those buildings on the same lot or just sell the lot and move on. 

I lived through Charley in Punta Gorda and let me tell you, there was no rhyme or reason to which home or business gets destroyed.

They can destroy carpets with pee and scratching, and scratch up windows, crown molding, everything.

I can see your halo but if you want a friend, I'll be your friend, I won't live in your house, I won't borrow your money and I won't destroy your house as a matter a fact I won't even live in the same state as you.I learned a long time ago you cannot let tenants be your friends, its sad to feel sorry for people but at some point people have to take responsibilty for their own lives.

. - can a building be destroyed down to its slab-imprint and then re-built as long as its footprint isn't added to laterally?)

I feel if get a new mailbox it will just get destroyed again.

Well whats the reason for most carpeting being destroyed in rental units?

Talk with the manager/owner of your local discount flooring shops and a lot of them will tell you about materials they have that you can be purchased for pretty deep discounts and what other investors are using locally.The remnant will be low cost and if it gets stained or destroyed then I can buy another one at a discount and "install" it.

And it's destroying our country.