out terrorism. russia observing national day of mourning right now. cnn s senior international correspondent matthew chance joins me live from moscow. where do things stand wit search and the investigation into what happened? reporter: in terms of the search, they ve got teams of rescue workers or of salvage workers at this point operating in the black sea. quite difficult conditions. the sea very deep where the plane went down but they have at least four ships on the surface scouring for any sign of debris, and they ve got submersibles as well and teams of divers working around the clock to try and locate the various parts of the plane and already there have been numerous big parts of the wrecked fuselage that have located, although it s not clear at this point that the black box flight recorders have been recovered and they will, of course, be essential determining what exactly went wrong, and also bodies pulled out of the black sea. they have to be identified, of course, but about