The Israeli submarine Dakar, carrying 69 sailors, disappears on this day in 1968 and is never seen again. The exact fate of this vessel remains a mystery to this day.

The Dakar was built at the height of World War II by H.M. Dockyard in Great Britain and commissioned as the HMS Totem by the British navy in 1943. Following the war, the submarine was modified, adding 12 feet to its length and removing some of its gun decks. Israel bought the sub, along with two other similar ones, from Great Britain in 1965. On November 10, 1967, the Israeli navy officially launched it as the Dakar. Following tests near Scotland, the Dakar was scheduled to journey to Haifa in Israel for an official ceremony in early February.

As the Dakar moved toward Haifa, it was supposed to radio its position to the command center in Israel every day. As it passed Gibraltar and moved into the Mediterranean Sea, Lieutenant Commander Ya’acov Ra’anan, in charge of the Dakar, requested permission to arrive in Haifa early on January 28. On January 24, though, the Dakar passed the island of Crete and radioed its position for the last time.

There was an additional signal from the Dakar just after midnight on January 25 and then--nothing. After the sub missed its scheduled signaling, unsuccessful attempts were made to contact the Dakar throughout the day. The following day, an international search-and-rescue operation began. Forces from the United States, Greece, Turkey and Lebanon all tried to find the Dakar for five days before giving up. Israel continued the search on its own until February 4. Despite some speculation that the submarine was deliberately sunk, the Dakar’s whereabouts remain a mystery.

Israel proclaimed March 4 a national day of mourning and it was declared that all 69 sailors on board the Dakar were considered dead under Jewish religious law. A monument to the crew was later built on Mount Herzel in Jerusalem.