Twitter parts with 4 key execs in latest sign of turmoil

Four of Twitter's key executives are leaving the company in an exodus that has escalated the uncertainty facing the messaging service as it struggles to broaden its audience and lure back disillusioned investors.

Twitter CEO Jack Dorsey announced the management shake-up late Sunday after technology news site Re/Code reported the changes earlier in the day.

Dorsey described the departures as voluntary, a characterization that three of the four exiting executives echoed in their own posts.