out with the investigation. the formal request hasn't been made, but one area they could help the egyptians in is analyzing a sound heard on the final moments of the voice recorder. a loud bang is heard. now u.s., u.k. officials believe this is the sound of a bomb exploding. egyptians on the other hand are saying it could be an engine exploding or battery. it could be a bomb. they just don't know and they want this investigation to continue. they are also analyzing the debris still out there where the plane crashed looking for signs of an explosions. so far we have not heard if they found any residue. a lot of scrutiny at the airport. the sharm el sheikh airport behind me. we have seen planes taking off all day. we have seen the russian security team on the ground assessing the security and making sure it is up to standards and if a bomb