Bujumbura - Thirteen crew of a Burundian vessel are feared to have died on a return trip from Tanzania, the maritime authorities said Thursday.Maritime authority director Melchior Nahimana said the boat belonging to Burundi's Tanganyika Transport Company had gone missing on Lake Tanganyika after leaving Kasanga port in Tanzania on Tuesday.The boat was returning from Zambia and made a stopover in Tanzania. It was not carrying passengers. Only one of the 14 crew on board was rescued. He was in too poor a condition to give details on what had happened.The authorities did not say whether the boat had sunk or give details on the rescue. It was not known if the boat had taken cargo or passengers to Zambia.