(Photo: Guampedia: "8 Dec. 1941 attack on Guam begins")
On December 7/8, 1941 (depending on which side of the International Dateline the location falls), Imperial Japan attacked not only Pearl Harbor, but also Guam, Manila, Midway, Hong Kong, Thailand, Shanghai, Wake, Singapore, Dutch East Indies, Malaya, and Burma.
Two months prior, the U.S. military anticipated and prepared for the attack on Guam:
In October 1941, most of the U.S. military and all the white dependents were evacuated from Guam. The remaining U.S. troops left on the island were given instructions to surrender to the Japanese forces. The Guam Insular Guard was not informed.Historian Hope Cristobal, former Guam senator, adds this from Destiny's Landfall by Robert Rogers, Page 163, Chapter 10 - "The Way of the Samurai 1941 - 1944":
The Guam Insular Guard lost 19 Chamorro men fighting the Japanese Imperial Army that landed on our island on the morning of Guam's biggest holiday, the Feast of the Immaculate Conception, celebrating the patron saint of the island, Santa Marian Kamalen.
My main source at hand is from a local Guam publication series, "Hale'Ta: Governing Guam: Before and After the Wars" by the Government of Guam 1994 Political Status Education Coordinating Commission. They produced a curriculum of political status studies for the island schools:
...Perhaps the most dramatic evidence of impending trouble came in late October 1941, when the Americans evacuated their wives and children from Guam. More than 100 dependents of American military personnel and the wives and children of the employees of at least two American-owned companies, Atkins Kroll and Pan American, were moved to Hawai'i and other American ports. No Chamorros were among the evacuees, although a number of local residents sought to leave the island at the time.Another source: Guam: The History of Our Island, by Pedro C. Sanchez (~1987). This is one of the older, more comprehensive histories, though it may be a bit of the colonized mindset:
...At about 8:15 that morning (December 8, 1941), nine silvery planes flew over Agana....the invading Japanese planes droped bombs at Sumay...
...during the very early morning hours of December 10, some 5,000 battle-hardened Japanese troops seized the island. A special force of about 500....blasted its way into Agana, cutting down everything in sight. At least 30 persons, most of them Chamorros, were killed before the special force reached the heart of Agana....armed only with three antiquated machine guns, a few sidearms and about 95 Springfield rifles of WW1 vintage, the Chamorro Guardsmen fought the invading Japanese Army until their small supply of ammunition ran out.
...in mid-1941, as war talk became more pronounced and as the threatening situation in the Pacific escalated, the US Government ordered the evacuation of all American military dependents from Guam. On October 17, 1941, when the USS Henderson sailed out of Apra Harbor, all American dependents left the island...
While the local Navy establishment took steps to prepare for war with Japan, officials kept the Chamorros totally in the dark about the worsening situation and about precautions being taken by the Navy command.
Dawn on Monday, 8 December 1941, on Guam, over 2,300 miles west of the international dateline, came four hours after the sunrise on Sunday, 7 December, at pearl Harbor, about 1,400 miles east of the dateline...And on page 161, Chapter 9 - "The Quest for Identity 1918 - 1941":
Earlier, on 17 October, the last American military dependents, 104 women and children, departed Guam on the USS Henderson except for one pregnant navy wife, Mrs. J.A. Hellmers. The last issue of the Guam Recorder in November 1941 did not say a word about the threat of war, but the cover showed the Henderson departing full of American families with the word "Aloha" alongside. Many Chamorros, alarmed by the evacuation and by blackout drills, began hoarding food, and some began to move to their lanchos for safety in anticipation of a Japanese attack."(Martha Duenas manages a listserve on Chamorro issues. Hope Cristobal, featured in Vanessa Warheit's documentary film, The Insular Empire: America in the Marianas. is a historian, museum director, former Guam Senator, and creator of Guam's Commission on Decolonization. For the past thirty years she has been struggling to reconcile Guam's dependence on the US military with the cultural and political survival of the Chamorro people.)