The cargo ship War Sun was built in 1918 at J. F. Duthie & Co., Seattle, Washington, her owners were to be the British government, but before she was completed she was purchased by the U.S. government for use as a transport and renamed Westover. She sailed to the east coast carrying lumber and flour and after discharging her cargo she was commissioned into the U.S. Navy on May 22, 1918 as USS Westover ID-2867. Her first military voyage was to take her to Brest, France with a cargo of U.S. Army supplies (including trucks, explosives, aircraft and even locomotives). They departed New York in convoy on June 28 however only two days out of port she developed engine trouble. Rather than turn back they dropped out of the convoy and continued at a much slower speed unescorted.

After passing a group of destroyers in mid ocean the Westover moved closer to the danger zone off the European coast. As they approached the Bay of Biscay on July 11, 1918 at 7am the constant drone of the engines was broken up by the sound of a torpedo exploding amidships on the starboard side. Fires broke out and the ship became unmanageable as the steering gear was damaged. Attempts to halt the flames and the inflow of water were useless and soon the commanding officer, Lt. Commander Alexander F. Ogilvie gave the order to abandon ship. Just after this a second explosion, thought to have been caused by an internal source, tore through the ship.

With many men injured, some whose feet were burned by the red hot steel plates others with broken bones and other injuries of varying degrees, began to lower the lifeboats. Six were lowered, but tragically the forward line on the number 4 boat gave way dumping over a dozen men into the water. The seas were heavy and several men, including the Assistant Paymaster and an Ensign were drowned.

The men in the other boats gathered themselves together to survey their situation. A third explosion, thought to have been a second torpedo, erupted in the after section of the ship where the ammunition was held, the magazine exploded throwing the deck gun and much of the deck cargo into the sea, the ship went down less than two minutes later. Eleven of her crew went with her.

After the ship had gone SMS U-92 broke the surface, Kapitänleutnant Günther Ehrlich and his men approached the survivors and questioned them asking for the ship's officers, none of which were given up. One man, a Yeoman named Fink, spoke German and was taken aboard the submarine. When Ehrlich was finished interrogating him he was sent back to his lifeboat, but while he was moving between the two vessels his hand was caught between them and badly injured. The Germans handed over some bandages for his injured hand and then left the area.

The eighty-two men and the ship's mascot, a dog named Westy, were in open boats almost 400 miles from Brest in a heavy sea. The sail on one of the boats had been burned so badly it was useless so it was taken in tow. The sea caused the line to part several times and later this boat lagged far behind the others. All the lifeboats became separated before morning, but all would make land. The lagging lifeboat was picked up by a destroyer some 150 miles from land, the others reached the French coast four days later, some being picked up by French fishing boats just outside Brest. After landing the wounded were taken to U.S. Navy Base Hospital #5 in Brest where they were treated. Sadly Lt. Commander Ogilvie reportedly committed suicide about a year later while at sea, it was said the effects of the loss of the Westover was the primary cause of his decline.