Captain Tollefsen was survived by his wife, Muriel, and two children, Astrid, 20 months, and Thomas, 9 weeks. He was also survived by his mother, Mrs. Emilie Tollefsen.
The Valencia was fishing near the Nantucket Lightship on November 13, 1938, when the ship began to fill with water. As Captain Sigvart Tollefsen climbed the mast to fasten a blanket as a distress signal, he slipped, hit the dory and fell into the water. The remaining crew members--John Knutsen, George Jacobson, and Nels Adland--launched a dory and found the captain, it was later determined that he died of exposure. They took turns rowing and bailing, headed toward the lightship. After 34 hours, they reached the lightship at ten the next night. They were fed, warmed, and given beds. The Valencia had survived the September hurricane, when it was tied up at Hathaway's Wharf in Fairhaven.