At least 15 people have died and 43 remain missing after a ferry sank off the southern coast of the Philippines, authorities said. The Philippine Coast Guard reported that 316 passengers were rescued after the ferry M/V Trisha Kerstin 3 went down near Balukbaluk Island off Basilan province while sailing from Zamboanga City to Jolo. Rescue teams continue search operations as the cause of the sinking remains unclear. An investigation has been launched.