In the morning on 7 March 1942 the unescorted and unarmed Cardonia (Master Gus W. Darnell) witnessed the sinking of Barbara by U-126 only seven miles away and tried to escape by increasing the speed and altering course towards the coast. The ship evaded two torpedoes fired at 10.47 and 10.48 hours, zigzagged and laid an improvised smoke screen. The U-boat opened fire with the deck gun at 10.54 hours and fired 56 rounds until the ship caught fire, stopped and the ten officers, 26 crewmen and two passengers on board abandoned ship in one lifeboat and three rafts. The shelling killed one crew member, carried away the radio antenna and mainmast and damaged the steering gear. At 12.16 hours, a coup de grâce was fired that hit amidships on the starboard side and caused the ship to sink in three minutes five miles west-northwest of the St. Nicholas Mole, Haiti.
The 20 crew members and two passengers in the boat made landfall after about six hours at St. Nicholas. The remaining 15 crew members on the rafts were picked up by USS Mulberry (AN 27) on 8 March and taken to Guantanamo Bay, Cuba.

The master Gus Warren Darnell was awarded the Merchant Marine Distinguished Service Medal for his actions during and after the attack. He was killed when his next ship, the Tillie Lykes, was sunk by U-154 (Kölle) on 28 June 1942.