a critical point. and signing off. the latest running late night host says he s retiring. you re watching cnn newsroom. we want to welcome our viewers in the u.s. and around the world. our top story, an underwater search for signs of malaysia airlines flight 370 is under way now in the indian ocean. all together 14 aircraft and nine ships will coma area of more than 240 kilometers. but right now they are towing pinger detectors. right now from perth, australia, matthew joins us. we know the batteries powering the signal they re listening for will soon go dead.