STOCKHOLM/COPENHAGEN—Two Danish crew members of a capsized barge were missing in the freezing Baltic Sea on Monday after an overnight collision with a British vessel in a busy maritime route off Sweden. With the pair unlikely to survive long in water temperatures around 4 Celsius, rescue boats and a helicopter hunted for hours. There was also hope they might still be inside an air pocket within the hull of the overturned Karin Hoj. The 55-metre Danish barge and 90-metre Scot Carrier were sailing in the same direction off the island of Bornholm when they crashed in fog and darkness at 3.30 a.m. (0230 GMT), maritime agencies in Denmark and Sweden said. At least nine boats and a helicopter combed waters near the wreckage-strewn site, while the overturned Karin Hoj was towed away to shallower waters where Swedish divers were ready to investigate the hull without risk of being dragged down. …