kristin dahlgren joins us from boston. what are we learning about the rescue efforts now?scue efforts are being directed. at 1:00 p.m., over there will be where the presser is being held, so we are hoping to learn more. to this point, we know they have aircraft and vessels on their way out to the area searching. they have used sonar buoys trying to listen for any sign of the submersible, which was headed down to the titanic wreck, 13,000 feet beneath the ocean. let's talk about the some of the risks. the pressure there is about the equivalent of being beneath an empire state building made of solid lead, and so extreme pressure is what they are dealing with. this is a difficult rescue operation. this is what my colleague, tom costello, talked to the admiral running this operation talked about. >> we put all the assets on finding the submersible and the people in it. when something happens on the high seas it gets complicated, and that's why we pressed hard to get aerial assets to search for it. >> reporter: a very difficult operation going on. as for the people who were onb