Robotic submarine deployed in search for plane

PERTH, Australia (AP) - Search crews sent a robotic submarine deep into the Indian Ocean for the first time today after failing to pick up any signals from the missing Malaysian airliner's black boxes for six days, the leader of the search effort said. Meanwhile, officials were investigating an oil slick not far from the area where the last underwater sounds were detected, said Angus Houston, the head of a joint agency coordinating the search off Australia's west coast.