MANILA, Philippines — A member of the Abu Sayyaf kidnap-for-ransom group captured after a gunfight at sea died in a hospital yesterday. Abu Ayub, 22, died of a heart attack, said Gen. Ernesto Carolina. The military said Ayub and three other survivors of the gun battle told them their leader, Abu Sabaya, was severely wounded before disappearing in the water. His body has not been found.