What we know and don't know about downed Russian jetliner

Michael Morell, a former number two at the CIA and now CBS News' senior security analyst, sat down with "CBS Evening News" anchor Scott Pelley on Wednesday. They discussed the possibility that the Islamic State of Iraq and Syria (ISIS) planted a bomb on the Russian plane that crashed over Egypt's Sinai desert killing 224 passengers.

Michael Morell. CBS News

Morell said the U.S. intel picked up conversations between ISIS members saying they brought the plane down, but the conversations were not specific enough.

To see what Morell has to say about what may have brought down the plane and what we know so far, watch the video above.