This primary source comes from the Records of the Office of the Chief Signal Officer.
National Archives Identifier:
524394Full Citation: San Francisco Earthquake of 1906: Burning of San Francisco. Looking toward the Bay; 4/1906; Records of the Office of the Chief Signal Officer, Record Group 111. [Online Version, https://www.docsteach.org/documents/document/san-francisco-earthquake-of-1906-burning-of-san-francisco-looking-toward-the-bay, May 10, 2024]