Scott Roberts of Bloomingdale has on the BACA blog part of an article from the Washington Business Journal mentioning these two buildings.
Langston has been closed for like, ever.
Slater. Slater had/has some children's care inside that crumbly building. I'd shift some of the responsibility to the tenants on its state.
There are several other buildings throughout the city that are in good locations where the city lets the buildings rot. Giving them a historic designation did zero in making them functional. It just makes them more expensive to repair.