>> flight 370 was delayed mthen missing then feared crashed. this plane had been hijacked. our chief intelligence correspondence has been tracking that story from washington. >> within hours of the disappearance investigators focus on two passengers who use stolen passports aboard flight 370. the men purchased the tickets t through an iranian middleman. >> intelligence officials emphasize while the men profiles run through multiple data bases no positives were found. it was later determined one of the iranians were in flight training they would not rule anything out. >> one is hijacked. >> u.s. officials open to the possibility of terrorism.