Im Errol Barnett here with you for the next two hours on cnn newsroom. We begin this hour in egypt where russian investigators are set to began examining egyptian Airport Security in the coming hours. Over the next few days, aplan to order all of egypts major investigators. This is amid suspicions that a bomb took down the jet. A u. S. Official says theyre all but certain but egyptian Authorities Say theyre not sure. Lets go to ian lee who joins us live this morning. Ian, egyptian fishofficials reluctant to put the plam blame bomb. What do we know . Reporter well, we know there was a loud sound on the voice recorder right before it went silent and the plane crashed. There was theories about the sound. The predominant theory is about a bomb. Egyptian officials have been reluctant to say its a bomb. Theyre saying it could be from a mechanical issue or a battery exploding, but what will really determine this is further analysis of that sound, which that help is being offered too not only