reporter tina krause says the company is defending its aircraft and its crew. >> reporter: u.s. intelligence sources tell cbs news the russian jetliner that crashed in egypt was likely not shot document while some sources are not ruling out a possible bomb on board, the u.s. director of national intelligence said there is no proof terrorists are to blame. >> we don't have any direct evidence of any terrorists involvement yet. >> reporter: russian airline officials contradicted egyptian reports that the pilot requested to land at the nearest airport because of technical issues. metro jet bosses say there was no mechanical issue or pilot error and some catastrophic event caused the plane to dive into the des certificate, killing all on board. the bodies were brought back to st. petersburg upon. the jet laner broke apart in mid-air about 23 minutes into the flight. investigators hope the black box flight recorders hold the clues they need to solve the worst air disaster in russian history. tina krause, cbs news. >>> claims from islamic militants who say they shot down the plane hav