I have never been in the buildings but driven around the perimeter and talked to the police trying to find out about the place. One of my friends had a brother who spent his life there because that's where people were sent when there was a big TB epidemic. From talking to the curator at the Duvall Mansion, I was told that there were tunnels that connected all of the buildings so that staff, patients and supplies wouldn't be exposed to bad weather. The curator said that there was a mob-style murder in the tunnels in the 60's and the tunnels were shut down, so in the 70's the DC government turned it over to MD because they hadn't taken care of it. People went through stripping copper pipes out and stealing whatever equipment they could salvage. It became a spot for criminals as well. Police are there to keep people out so that if someone gets hurt, they can't sue MD. The place is a death trap because it hasn't been taken care of. It was a mental hospital BEFORE the TB hit and also a regular hospital.