General George C. Marshall, Chief of Staff (U.S. Department of Defense, Washington, D.C.), sent a 26 February 1942 memorandum to President Roosevelt regarding the incident known as the “Battle of Los Angeles.”
Quote from the document:
“MEMORANDUM FOR PRESIDENT:
The following is the information we have from GHQ at this moment regarding the air alarm over Los Angeles of yesterday morning:
‘From details available at this hour:
‘1. Unidentified airplanes, other than American Army or Navy planes, were probably over Los Angeles, and were fired on by elements of the 37th CA Brigade (AA) between 3:12 and 4:15 AM. These units expended 1430 rounds of ammunition.
‘2. As many as fifteen airplanes may have been involved, flying at various speeds from what is officially reported as being ‘very slow’ to as much as 200 MPH and at elevations from 9000 to 15000 feet.”
The document can be found on Page 236 (Page 238 in the printed book).
The famous 25 February 1942 “Battle of Los Angeles” photo