Maybe B O's good friend, William (Bill) Charles Ayers, former head honcho of the weather underground, has something to do with this.
What is the Weather Underground?
Nobody was hurt outside the organization in the attacks by the defunct organization, which the FBI labeled a "domestic terrorist group". However on February 16, 1970, in which a pipe bomb filled with shrapnel detonated on the ledge of a window at the Park Station of the San Francisco Police Department. Brian V. McDonnell, a police sergeant, was fatally wounded in the explosion, and Robert Fogarty, another police officer, was severely wounded in his face and legs and was partially blinded. The Weathermen, along with the Black Panther Party were initially investigated for the murder, which was never solved.