Alcatraz Federal Penitentiary in January 1934. The hospital facilities were checked by three officials from the Marine Hospital of San Francisco. The Bureau of Prisons personnel arrived on Alcatraz in early February; among them was Loring O. Mills, acting chief clerk. In April 1934, the old material was removed from the prison, holes were cut in the concrete and 269 cell fronts were installed, built using four carloads of steel ordered from the Stewart Iron Works. A legend at the works is that a shipment of cells and iron accidentally fell into San Francisco Bay during transportation from San Francisco Dock to Alcatraz
Alcatraz Island 1906 San Francisco earthquake, civilian prisoners were transferred to Alcatraz for safe confinement. On March 21, 1907, Alcatraz was officially designated as the Western U.S. Military Prison, later Pacific Branch, U.S. Disciplinary Barracks, 1915. In 1909 construction began on the huge concrete main cell block, designed by Major Reuben Turner, which remains the island's dominant feature. It was completed in 1912. To accommodate the new cell block, the Citadel, a three-story barracks, was demolished down to the first floor, which was actually below ground level. The building had been constructed in an excavated pit (creating a dry "moat") to enhance