On June 22, a North Korean Yugo-class became disabled in South Korean waters. About 11 miles east of Sokcho and 21 miles south of the inter-Korean border, the submarine became tangled in a fishing drift net. The North Korean sailors attempted to free the submarine to no avail. The surfaced and disabled submarine was observed by South Korean fishermen who notified the South Korean Navy of their sighting. A corvette was promptly dispatched to intercept the North Koreans. The submarine was towed by the corvette back to the navy base at Donghae with its crew still inside. However, the submarine sank on its way into port. It is still unclear if the submarine sunk due to damage sustained or if it was scuttled. The next day, the North Korean state-run Korean Central News Agency announced that a submarine had been lost in a “training accident.”
On June 25, the submarine was salvaged by South Korea. It had sunk to a depth of approximately 30 meters. The bodies of nine North Koreans were recovered from the submarine. The five sailors who crewed the submarine were apparently executed. Four of them had been shot in the head. “It appears that four men, including the commander, shot the five men to death, then committed suicide,” said the South Korean Joint Chiefs of Staff Lt. Gen. Chung Young Jin.