William Gonzalez, 59, president and chief executive officer of two-hospital Spectrum Health Care in Grand Rapids, Mich., abruptly resigned last month from the hospital system he was instrumental in creating.
Gonzalez, who didn't respond to a request for comment, didn't publicly reveal his reasons for his departure or his future plans.
Spectrum Chief Operating Officer Terrence O'Rourke was named interim president and CEO until a permanent replacement is named.
"We're all devastated," said O'Rourke, 61, who previously held the CEO post. "Bill has chosen not to comment (on his resignation). I don't know what the motivations were. The job is very difficult, and I speak from experience."