English: Looking west-northwest at the ground floor of the south facade of the J. Edgar Hoover Building (the headquarters of the Federal Bureau of Investigation) on Pennsylvania Avenue NW in Washington, D.C., in the United States. Urban planners were concerned that the highly secure building would be a "dead space" on heavily trafficked, historic Pennsylvania Avenue NW. They argued that an arcade should run along the south side of the structure, and that street-level retail exist in the building. Concerned about the violence common in the United States in the late 1960s, the FBI resisted both schemes. Federal agencies approved the FBI's design, which left the ground floor of the FBI building on Pennsylvania Avenue NW a blank wall. The FBI has refused to even permit artwork to adorn these spaces, for fear that crowds would be attracted to the building and compromise its security.