>> so, when they're searching, all those probabilities are, you know, taken into account. are they in a raft? you know, they could be floating on a piece of equipment. they could be, you know, if they're wearing life jacket, you know, they could be in the water, all those different things we take into consideration. so, that's why we surface assets as well as air and get out there and do a very intensive search. >> okay. senior chief petty officer michael o'berry, stand by. he's with the u.s. coast guard. breaking news in right now that we're covering. the deepwater horizon, the oil rig that had the explosion on it, has sunk below the surface in the gulf of mexico. we'll continue our coverage of this in a moment. [ male announcer ] nature valley