April 30, 1967, is a day many Minnesota residents refer to as 'Black Sunday.' A storm passed through the area causing waves as high as 20 feet on Lake Superior, here, with winds gusting up to 45 mph across the 36-degree water. The Coast Guard rescue team of Culbertson, Callahan, and Prei were dispatched during the storm to search for three brothers who had been reported missing. Eric, Arthur and Nathan Halverson had last been seen on the North Pier break wall of the Duluth Harbor entry. The Coast Guardsmen tied themselves together, spaced 25 feet apart and struggled to the end of the pier but were unable to reach the boys before they were swept over the side. As they traversed back across the pier, a large wave crashed into the team and swept Culbertson over the side, taking his life.