At 07.16 hours on 28 Nov, 1942, the unescorted Alaskan (Master Edwin Earle Greenlaw) maintained a zigzag course in heavy rain, as one of the lookouts spotted the wakes of two torpedoes from U-172. One torpedo missed and the other struck the ship amidships on port side. The explosion destroyed the main engines, both port side lifeboats, knocked down both aerial antennas and the topmast. It also buckled the deck, destroying the deck gear and machinery. The Alaskan quickly listed to port but did not sink. 10 officers, 32 men and 16 armed guards (the ship was armed with one 5in, one 3in, four 20mm and two .30cal guns) were ordered to leave the ship 25 minutes after the attack. The #3 lifeboat swamped and four men drowned.
Then U-172 surfaced and shelled the ship at the rate of one shot a minute. She fired about 60 rounds, hitting the ship about 40 times, until the burning Alaskan rolled over and sank bow first at 08.10 hours about 800 miles northeast of Natal, Brazil.

The lifeboat #1 was launched with 18 crew members and 11 armed guards and pulled away from the ship and made a landfall at Salinas, Angola on 15 December, where one of the armed guard died in the hospital and was buried there. 10 crew members and three armed guards left the ship on a raft and were picked up by the Spanish steam merchant Cilurnum on 13 December and were brought to Las Palmas, Canary Islands. They stayed there for 25 days before going on to Cadiz and finally to Gibraltar.
The master, the armed guard commander, the 2nd mate, the radio operator, one armed guard and four crew members left the ship on a raft. U-172 came alongside and took the master aboard. After the usually questions, Emmermann told him: Sorry we sank you, but this is war. Why don´t you tell America to get out of the war., before he was allowed to go back to the raft. On the next day, they righted a swamped lifeboat and transferred into it. They spent 39 days at sea before making a landfall south of Cayenne, French Guiana (2000 miles away) on 5 Jan, 1943. They followed the coast until they reached Cayenne and made land safely with the help from a fishing boat. All were hospitalized and treated well by the local government officals. A few days later they were moved out of French Guiana by aircraft. In all, two officers, five men and one armed guard lost their lives.