On 26 January, "Thresher" made radar contact with a small convoy and soon spotted two ships steaming along beneath the overcast night skies. At 00:11, "Thresher" fired three bow torpedoes at a 1,266-ton freighter, then bent cleared the area. Her "fish" scored a bullseye, and the quarry disappeared within a minute. A second spread, 35 seconds after the first, claimed a 2,205-ton freighter. A third target made off to the south at high speed, "spraying the ocean with five-inch ammunition". Resuming the approach at 00:20, "Thresher" doggedly tailed the Japanese ship for four hours before reaching a favorable attack position. Firing her last torpedoes at 04:46, "Thresher" began to build up speed and had just commenced a turn when one torpedo struck the enemy ship, causing a tremendous explosion. The blast slowed the freighter, but its tremendous concussion stopped "Thresher" dead in the water. All four main engine overspeed trips were actuated; cork insulation flew; lights broke; clocks stopped; and water poured down the antenna trunk. By the time "Thresher" regained battle readiness, the enemy was too far away to encourage further pursuit. Well within the range of shore-based aircraft, "Thresher" quit the chase. Escorts, alerted to the fact an American submarine was prowling in the vicinity, arrived on the scene and conducted a three-hour-long, futile, depth-charging.