The Mare Island-built USS California also sank during the attack. It was refloated and repaired.
Mare Island’s role in Pearl Harbor
On Sunday morning, Dec. 7, 1941, powerful antennas on the Mare Island shipyard picked up an urgent radio-telegram meant for U.S. Navy ships operating 3,600 miles away near Hawaii — “AIR RAID ON PEARL HARBOR — THIS IS NO DRILL.” That was the first stateside word about the devastating surprise attack by Japanese warplanes.
The strafing and bombing started just before 8 a.m. Hawaii time, or 10:30 a.m. PST on Mare Island under the time zone system used in 1941. The radio message went out immediately from Pearl Harbor, and was relayed to top Navy brass in San Francisco by senior telegrapher Van Dayton, on duty in Mare Island’s communications office.
Less than an hour later, at 11:20 a.m. PST or 2:20 p.m. EST, President Franklin Roosevelt’s press secretary, Stephen Early, on a telephone hookup to Associated Press, United Press and International News Service offices in the nation’s capital, made the information public. A flood of national news about Pearl Harbor followed, starting with bulletins from the three news services. That included an all-caps flash filed at 2:22 p.m. EST by AP editor William Peacock, who repeated Early’s disparaging term in common use to describe the Japanese — “WHITE HOUSE SAYS JAPS ATTACK PEARL HARBOR.”
The radio-telegram was sent on orders from Lt. Cmdr. Logan Ramsey, operations officer for the Pacific Fleet Air Wing at Pearl Harbor, after he witnessed one of the first Japanese planes flying in low to drop a bomb. At first, he thought it was a U.S. plane being flown by a reckless pilot, but then he heard the explosion of a delayed-action bomb.
Ramsey’s first radio message was followed by a second one, in the same all-caps format, that stated, “WE ARE AT WAR WITH JAPAN — THIS IS NO DRILL.” Then a third message arrived, ordering Mare Island to immediately initiate a war plan that had been prepared in advance and locked in a safe in a shipyard office.
Mare Island historian Dennis Kelly says that caused problems — the staffer who had the safe’s combination was vacationing at Lake Tahoe. A few hours later, a California Highway Patrol trooper showed up at the door of the man’s Tahoe cabin with orders to return at once to Mare Island and open the safe.
The attack by Japanese planes and submarines at the ill-prepared Pearl Harbor base resulted in more than 3,500 U.S. casualties, including 2,403 killed. Twelve ships sank or were beached, and nine other vessels were damaged. More than 180 U.S. aircraft were destroyed, and more than 150 others were damaged.
The following day, in an address to a joint session of Congress, President Roosevelt called Dec. 7, 1941, “a date which will live in infamy.” Congress then declared war on Japan, abandoning the nation’s isolationist policy and ushering the U.S. into World War II. Within days, Japan’s allies, Germany and Italy, declared war on the United States, and the country began a rapid transition to a wartime economy.
The attack on Pearl Harbor galvanized the nation, resulting in an overnight refocusing of all U.S. military, economic, industrial, and scientific activity. Work on Mare Island ratcheted up to a level never seen before or since. The day after the attack, crews started pouring cement for bomb shelters on Mare Island.
Soon, the Mare Island-Vallejo area was “bristling with anti-aircraft batteries” and “a herd of barrage balloons was tethered above the island, their purpose being to discourage attack by low-flying planes,” author Arnold Lott wrote in “A Long Line of Ships,” his book detailing Mare Island’s history.
Civilian shipyard employment soared to about 44,000 during the war, with workers coming from almost every state. Sailors, Marines, and Army soldiers arrived by the thousands, and Vallejo’s pre-war population of about 30,000 tripled.
A third of the wartime population lived in hastily constructed housing projects scattered around the city — projects that were filled as soon as they were built. Some workers slept in cars, on porches, in hallways, bathrooms, abandoned shacks, barns, garages, or even on the docks. About 300 buses went out in a radius of 75 miles six times a day to pick up workers who lived outside Vallejo.
Mare Island was a key part of a San Francisco Bay area shipbuilding complex that was the largest in the world. During the war, Mare Island workers built 17 submarines, 31 destroyer escorts, 33 assorted small craft, and 301 landing craft, and repaired more than 1,200 damaged vessels — including several ships damaged in the Pearl Harbor attack. One of the vessels repaired at Mare Island was the USS Indianapolis, which left in mid-July 1945 on the most secret mission of the war — delivering components of “Little Boy,” the world’s first operational atomic bomb. The components were unloaded at the island of Tinian on July 26, 1945. Four days later, the Indianapolis headed to Leyte Gulf in the Philippines, was torpedoed and sank. Of the 1,196 men aboard the big cruiser, about 900 made it into the water. After almost five days of shark attacks, starvation, thirst and exposure, 317 men were rescued.
On Aug. 6, 1945, an American B-29 bomber dropped “Little Boy” over Hiroshima. The explosion immediately killed about 80,000 people. Three days later, a second B-29 dropped another A-bomb on Nagasaki, killing an estimated 40,000 people. Japan’s Emperor Hirohito announced his country’s unconditional surrender in an Aug. 15 radio address, and formal surrender documents were signed Sept. 2 aboard the USS Missouri in Tokyo Bay.
Brendan Riley
Solano Chronicles – December 7th, 2025
Urgent radio-telegram alerted Navy ships and Mare Island to the attack on Pearl Harbor.
Front page of Vallejo newspaper the day after the Dec. 7, 1941, attack.
The USS Arizona, one of many ships sunk in the Pearl Harbor attack.
Photo of the attack on Pearl Harbor.
1970 Mare Island Grapevine account of Van Dayton's role in alerting top Navy brass about the attack. Dayton was senior telegrapher on Mare Island.
President Roosevelt, in wartime visit to Mare Island, sees Japanese submarine captured during Pearl Harbor attack.
