purely circumstantial. u.s. officials don't have the hard evidence they normally would at this stage, explosive residue on the debris or bodies with shrapnel, possibly indicating an explosion, until they do so u.s. officials will also refuse a definitive conclusion, jake. but as you have heard so many officials here in the u.s. and israeli and in the uk they're at least willing to go so far as that is most likely conclusion. >> 99% is pretty close to 100. jim sciutto, thanks. the british government says the luggage screening process at sharm el sheikh failed and that could be how isis or its affiliate in sinai potentially delivered a bomb to this plane. cnn international correspondent erin mclaughlin is in sharm el sheikh where this ill-fated flight took off. erin, you got a close look at what goes on behind the ticketing counter at the airport. tell us about it. >> reporter: hi, jake. that's right. we were given a tour of the security points throughout the airport including the luggage screening process as well as a room used to monitor cameras