At 19.38 hours on 13 Jun 1942 the unescorted Solon Turman (Master Frederick Ulstad) was hit by two G7a torpedoes from U-159, while steaming on a zigzag course at 14.5 knots about 100 miles north of Cristobal, Canal Zone. One day earlier, the ship had left a convoy of six ships to proceed independently. The first torpedo struck the port quarter at the #5 hold and the second hit at the #4 hold. The heavy explosions split the gun deck, snapped the after mast, brought down the radio antenna and threw pontoons, tanks and other deck cargo into the air. The ten officers, 34 crewmen and nine armed guards (the ship was armed with one 4in and four .50cal guns) abandoned the disabled ship in two lifeboats. One armed guard had been blown overboard by the second torpedo hit and was later picked up by one of the boats. The ship sank vertically by the stern about 25 minutes after the attack. In the meantime, the U-boat surfaced and offered food, water, medical supplies and cigarettes after questioning the survivors.
The survivors were picked up after 28 hours by the Colombian schooners Envoy and Zaroma, but the second assistant engineer accidentally fell overboard from the Envoy and drowned. On 15 June, all men were transferred to the American patrol boat USS PC-458 and landed at Cristobal.