On the morning of 5 September 1918, Mount Vernon and four destroyers were off France and steaming in a convoy toward the U.S. when Mount Vernon was attacked by U-82.
The German vessels' periscope was spotted 500 yd (460 m) off the starboard bow, by a man of Mount Vernon's gun crew; they immediately fired a round from the gun.

The shot was a hit.
Apparently unaffected by the shot, which reportedly did not harm anyone, U-82 surfaced.
The U-boat fired a single torpedo at Mount Vernon and then submerged.
The American captain ordered "right full rudder" but the ship could not turn fast enough and was hit.

The destroyers USS Winslow, Conner, Nicholson and Wainwright responded immediately and approached the battle area.
Once they arrived near Mount Vernon, they observed the damage from a large explosion on Mount Vernon′s side.

The German commander, seeing the fast-approaching American destroyers, decided not to follow up with a second torpedo, so no further damage to the U.S. auxiliary cruiser was sustained.
The four destroyers dropped depth charges for many minutes after Mount Vernon was hit, but they  failed to sink the U-boat, which slipped away.

Despite this, the American destroyers were credited with saving Mount Vernon from being  sunk.
Mount Vernon steamed safely back to Brest with the loss of 36 out of the 1,450 people on board.
Thirteen others were wounded; all of the American casualties were the result of the single torpedo explosion that flooded the engine room requiring the hatch to be closed to save the ship, but at the loss of engine room crew that had survived the initial torpedo impact.

The ship suffered considerable damage, but after immediate improvised repairs, she was able to return to Brest under her own steam with an allied warship for additional protection.
On the morning of 5 September 1918, Mount Vernon and four destroyers were off France and steaming in a convoy toward the U.S. when Mount Vernon was attacked by U-82. The German vessels' periscope was spotted 500 yd (460 m) off the starboard bow, by a man of Mount Vernon's gun crew; they immediately fired a round from the gun.
The shot was a hit. Apparently unaffected by the shot, which reportedly did not harm anyone, U-82 surfaced. The U-boat fired a single torpedo at Mount Vernon and then submerged. The American captain ordered "right full rudder" but the ship could not turn fast enough and was hit.
The destroyers USS Winslow, Conner, Nicholson and Wainwright responded immediately and approached the battle area. Once they arrived near Mount Vernon, they observed the damage from a large explosion on Mount Vernon′s side.
The German commander, seeing the fast-approaching American destroyers, decided not to follow up with a second torpedo, so no further damage to the U.S. auxiliary cruiser was sustained. The four destroyers dropped depth charges for many minutes after Mount Vernon was hit, but they  failed to sink the U-boat, which slipped away.
Despite this, the American destroyers were credited with saving Mount Vernon from being  sunk. Mount Vernon steamed safely back to Brest with the loss of 36 out of the 1,450 people on board. Thirteen others were wounded; all of the American casualties were the result of the single torpedo explosion that flooded the engine room requiring the hatch to be closed to save the ship, but at the loss of engine room crew that had survived the initial torpedo impact.
The ship suffered considerable damage, but after immediate improvised repairs, she was able to return to Brest under her own steam with an allied warship for additional protection.
Action of 5 September 1918