Berth 46 - S.S. Sansinena Explosion Site

Built in the postwar period as the world's first "Supertanker" dock, LA Marine Terminals Berth 46 gained notoriety as the sight of a massive explosion and fire involving the oil tanker SS Sansinena.

On December 17th, 1976, the 810ft SS Sansinena was completing oil discharge operations at Berth 46 and was sitting high in the water. Her crew began ballasting operations by adding seawater to her ballast tanks in order to bring the ship lower in the water and increase her stability, however this process caused the oil vapors from her cargo tanks to be displaced from the tanks onto her decks through open vents, and the calm winds in the harbor failed to disperse the fumes. As ballasting operations continued, the concentration of oil vapors on the deck and in the surrounding dock area steadily increased until 7:38pm, when something onboard the Sansinena sparked.

The resulting explosion obliterated the Sansinena, with flames racing across the vapor saturated deck and through the open deck vents into the cargo holds, which were all full of highly explosive residue and oil vapors. All 5 cargo tanks were exploded from the inside-out, showering the surrounding area with deadly shrapnel and massive pieces of hull, including the entire midship deck and deckouse section, weighing 2,500 tons. Buildings in the immediate area were flattened, and windows up to 25 miles away were blown out by the pressure wave. The hull of the Sansinena was split in half, and the bow and stern sections quickly sank, wreathed in a pool of burning oil and fuel.

LAFD ground and marine units were onscene moments after the explosion and began exhaustive efforts to fight and control the fire, which burned for over three hours until it was declared out at 10:20pm. The entire 6 member crew of the Sansinena aboard the ship eating dinner at the time of the explosion were killed, a further two crewmembers who were on deck and a dock watchman stationed at the ships gangway are still missing and presumed dead and 46 people in the surrounding area were injured, 9 severely.

Damage to the Sansinena was total, and the ship was eventually raised in sections and scrapped. Damage to Berth 46 was also extensive, and following the explosion it never reopened to supertankers and its infrastructure was dismantled and moved to different locations. Today, the berth remains and is usually vacant.

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