one-day loss in market value by a single company in wall street history yesterday. it was the company's worst day ever since becoming public after a sobering quarterly report slowing down revenue estimates and user decline sent investors heading for the his. shares closed down 19%, knocking $119 billion off the company's market value. that's a lot of money. mark zuckerberg personally lost an estimated $16 billion as a rule, falling three spots to number six on the list of the world's richest people. he's still pretty rich. no company in the history of the stock market has ever lost 100 billion in market value in a single day, but two came close, intel and microsoft back in 2000 on the edge of the dot-com bubble burst. >> i think the world will be watching the markets to see how and if facebook recovers. still ahead, a democrat senator claims russian hackers tried to gain access to her