The only fighting ship of the Cruiser and Transport Force that was sunk—in fact, the only large United States naval vessel lost during the war—was the armored cruiser San Diego (Captain H. H. Christy) sunk by a mine off Fire Island, N. Y., July 19, 1918.
Proceeding from Portsmouth, N. H., to New York, the cruiser was steering what was regarded as a safe course to avoid the submarines, then operating in Atlantic waters, and the mines they had laid. Lookouts, gun-watches, fire control parties were at their stations, the whole crew on the alert. There was no sign of any U-boat or mine.
Suddenly, at 11:05 a. m., there was an explosion at frame No. 78, on the port side well below the water line. "Full speed ahead," was rung by the Captain, who hoped the ship could be kept afloat, and the starboard engine operated until it was stopped by rising water.
Machinist's Mate Hawthorne, who was at the throttle in the port engine room, was blown four feet under a desk. He got up, closed the throttle on the engine, which had already stopped, and then escaped up the ladder. The lieutenant on watch in the starboard engine room, closed the water tight doors, and gave instructions to the fireroom to protect the boilers.
The vessel listed to port so heavily that water entered the gun ports on the gun deck. Listing 8 degrees quickly, the vessel hung for seven minutes; then gradually turned until 35 degrees was reached. At this time the port quarter-deck was three feet under water. The cruiser then rapidly turned turtle and sank.
Captain Christy was last to leave the ship. Going from the bridge down two ladders to the boat deck, he slid down a line to the armor belt, then dropped four feet to the bilge keel, and thence to the docking keel. From there he jumped into the water. The men cheered their captain as he left the ship. On the rafts they sang "The Star Spangled Banner" and "My Country 'Tis of Thee," and more cheers arose when the United States ensign was hoisted on the sailboat.
Two dinghies with six officers and twenty-one men pulled to shore, arriving at 1:20 p. m. The steamer Malden picked up 370 officers and men, the Bossom 708; the E. P. Jones 78. Six men were lost, three of these being killed by the explosion. The court of inquiry reported that "the conduct of the Captain, officers and crew was in the highest degree commendable," and that "the remarkably small loss of life was due to the high state of discipline maintained on board."
This was the last loss sustained by the Cruiser and Transport Force until September 5th. Then the troop-ship Mt. Vernon (Captain D. E. Dismukes) was torpedoed, but by splendid seamanship was taken to port under her own steam. The Mt. Vernon, homeward bound, was 250 miles from the coast of France when she was struck. The explosion was so terrific that for an instant it seemed that the ship was lifted clear out of the water and torn to pieces. Men at the after guns and depth-charge stations were thrown to the deck, and one gun thrown partly out of its mount. The torpedo struck fairly amidship, destroying four of the eight boiler-rooms and flooding the middle portion of the vessel from side to side for a length of 150 feet. The vessel instantly settled 10 feet increase in draft, but stopped there. This indicated that the water-tight bulkheads were holding, and she could still afford to go down two or three feet more before she would lose her floating buoyancy. The immediate problem was to escape a second torpedo. Depth-charge crews jumped to their stations, and started dropping a depth-bomb barrage.
Men in the firerooms knew that the safety of the ship depended on them. The shock of the explosion, followed by instant darkness, falling soot and particles; the knowledge that they were far below the water level inclosed practically in a trap; the imminent danger of the ship sinking, the added threat of exploding boilers—all these dangers and more must have been apparent to every man below, said Captain Dismukes, and yet not one man wavered in standing by his post of duty.
C. L. O'Connor, water tender, was thrown to the floor and enveloped in gas flames from the furnaces. Instead of rushing to escape, he turned and endeavored to shut a water-tight door leading into a large bunker abaft the fireroom, but the hydraulic lever that operated the door had been damaged and failed to function. Three men at work in this bunker were drowned. If O'Connor had succeeded in shutting the door, all would have been saved. Caught in the swirl of inrushing water, O'Connor was thrust up a ventilator leading to the upper deck.