National Security spokesman John Kirby speaking on a podium with an American flag behind him at a press conference
National security spokesman John Kirby said the AT&T cellular outage is being looked into.
  • AT&T cell service went out for tens of thousands of Americans on Thursday.
  • The reason for the outage isn't clear — and now the FBI, the FCC, and Homeland Security are looking into it. 
  • But US officials were told there's no reason to suspect a cybersecurity incident yet. 

A sudden cellular outage left tens of thousands of AT&T customers without service on Thursday — and now the feds are looking into it.