USS Seawolf (SS-197), under the command of LCDR A.M Bontier, was sunk by U.S. forces on 03 October 1944 while on her 15th war patrol. She was carrying supplies and 17 U.S. Army personnel to Samar, in the central Philippines.
On the morning of 03 October, a U.S. task group was attacked by the Japanese submarine Ro-41. USS Shelton (DC-407) was torpedoed and sunk in the attack.
Shortly after the attack, a plane from the escort carrier USS Midway (CVE-63), sighted a submarine on the surface, and dropped two bombs on it as it was submerging, even though the submarine was in an established safety zone for U.S. submarines. USS Rowell (DE-403) steamed into the area and detected the submerged Seawolf. Believing the submerged contact to be a Japanese submarine, Rowell attacked, even though the submarine tried to send a series of dashes and dots with her underwater signalling equipment. Rowell's attack resulted in an underwater explosion, and debris rose to the surface.
Seawolf was the only U.S. submarine known sunk by American forces in World War II. 102 men, including the 17 U.S. Army personnel, were lost.
After the war, it was learned by Ro-41 successfully escaped detection by US forces. She would be sunk with all hands by USS Haggard (DD-555) on 22-23 March 1945.
LCDR Bontier had been the Commanding Officer of USS Razorback when she was commissioned.