UnitedHealth: One of America’s biggest companies is imploding

By Matt Egan, CNN UnitedHealth Group, one of the US's biggest corporations and a member of the exclusive Dow Jones Industrial Average, is suddenly unravelling. The crisis engulfing UnitedHealth hit a crescendo this week when chief executive Andrew Witty stepped down abruptly for "personal reasons". UnitedHealth also swiftly abandoned its financial guidance, blaming skyrocketing medical costs. And then The Wall Street Journal dropped the hammer, revealing that UnitedHealth is under federal crimin