A motor vessel, the MV Joko Kodok, with 20 passengers on board, sank in Bangkau waters, Sumenep, Madura Island, East Java province, on Monday, causing the death of one passenger and the disappearance of four others, ANTARA reported. Fifteen surviving passengers had to be treated at a local health center, Sapeken Sub district Head Hainur Rasyid said here on Monday. The ill-fated boat captained by Masdanu, left Saebus Isle for Sapeken Isle at 7 am local time, with 20 passengers on board. However, when the boat reached Bankau waters, it developed engine trouble and then was hit by huge waves twice which caused the boat to capsize. "Local fishermen who heard about the accident, immediately rushed to the boat's location to help its crew and passengers," Rashid said.