submersible. >> wolf blitzer's here with a preview of "the situation room." search teams picked up two more sets of signals that could potentially be pingers from the black boxes. >> he's got a lot of experience in the area, mike deane, the deputy director of u.s. navy salvage and diving. we'll go in-depth, i guess -- >> was that on purpose? >> in-depth with him. you know, our chief national security correspondent had an exclusive with defense secretary, chuck hagel, live from beijing. they spoke about the search for the malaysia airliner and ukraine. a lot of news coming up. >> coming up in our money lead, the evidence has been scarce, resources enoous, who's paying for the hadn't of 370. minute as way from the news conference on the mass stabbings at a high school outside pittsburgh. we'll bring it live as soon as officials start talking. stay with us.