BY NOAKI SCHWARTZ, ASSOCIATED PRESS

This Jan. 21, 1921, image shows the SS Montebello being launched in East San Pedro, Calif. On Dec. 23, 1941, the S.S. Montebello was torpedoed by a Japanese submarine off the coast of Cambria, Calif., sinking the 8,272-ton tanker carrying 3 million gallons of crude oil that may still be in its holds.

AP Photo/California Department of Fish and Game

Two weeks after the attack on Pearl Harbor, a Japanese submarine shot a torpedo at an American oil tanker just off the California coast, sinking the ship and sending 3 million gallons of crude to the bottom of the ocean.

All 38 people on board were rescued in what remains an overlooked chapter of World War II — it was one of several attacks by Japanese and German forces on the U.S. mainland during the war.

The SS Montebello has sat mostly intact 900 feet below the surface with the oil remarkably still on board after seven decades. A mission to see how much of the oil remains in the hold of the 440-foot ship launches this week to help officials determine how to prevent the crude from leaking and marring the celebrated central California coastline.

“Eventually, something has to be done,” said Andrew Hughan, a spokesman with California Fish and Game. “If 3 million gallons of oil made its way to the beaches in front of Hearst Castle it would be a disaster for the area.”