Here's what you should know about Kroger CEO Rodney McMullen, who resigned following "a board investigation of his personal conduct."

Kroger board member Ron Sargent is taking the helm at the nation’s largest supermarket chain as questions about former CEO Rodney Mullen continue.

Kroger 's longtime leader Rodney McMullen abruptly resigned March 2 following a personal conduct probe initiated in February, ending a nearly 50-year career with the Cincinnati-based grocery giant. Here's what we know – and don't – about his career with the nation's largest traditional supermarket chain, and it's sudden end.