This is an updated version of a story first posted at 11:27 a.m.

Flint, Michigan -- The Don is gone.

Mayor Don Williamson announced today that he is "retiring," finally putting to rest weeks of speculation.

In an 11:20 a.m. news conference, Williamson cited health reasons for leaving office. His resignation is effective midnight Sunday. He took no questions from the media, and read from a prepared statement.

"Last month, I celebrated my third sinus infection in 13 months and my eighth kidney stone since Nov. 1. My doctors have told me that I should think about relaxing my schedule and reducing the demands on my time," said Williamson, 75.



Williamson, a multi-millionaire, said his life has been blessed with financial and political success.

"In my political life, I received the greatest honor of all, the trust and respect that the voters of this great city placed in me when they elected me mayor in 2003 and then re-elected me in 2007," Williamson said.Williamson praised new city administrator Mike Brown and deputy mayor Darryl Buchanan. Buchanan was present at the news conference but Brown was not.

Multimedia

• Audio of the Williamson resignation:











• Photo gallery: A look at Don Williamson in pictures through the years



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Video:

2007 Mayoral debate

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Video:

Williamson re-elected

Brown becomes acting mayor when Williamson leaves office and will lead the city until after an August election.

Williamson said there will be a lot of work for Buchanan and Brown as the city tries to deal with a "financial crisis."

"It has been a great pleasure and honor to serve the hometown where Patsy and I have lived our whole lives," Williamson said.



Rumors for weeks had been swirling that Williamson -- whose larger-than-life and often confrontational personality won him many of his supporters and his enemies -- would resign as mayor ahead of the Feb. 24 recall election.





More on Williamson's resignation

• Flint Mayor Don Williamson: 'Flint has done super fantastic'



• The next mayor: Michael Brown plans to make changes



• State takeover is not being considered



• Timeline: Don Williamson's reign as Flint mayor marked by success, controversy, disputes



• What's next?



• Don Williamson was either loved or hated. There was no in between



• Sen. John Gleason reacts to Williamson's resignation



• Flint City Council members react with joy



• Heller: The Don leaves office, but who is next?



• NAACP calls Darryl Buchanan's demotion racist, will meet today



• Recall organizers take credit for Don Williamson's resignation



Williamson repeatedly, and adamantly, denied those rumors.



And, many were surprised by Williamson's decision.

Genesee County Prosecutor David Leyton could only said "I'm shocked" when told of Williamson's resignation.

Genesee County Sheriff Robert Pickell said he was "absolutely shocked that the mayor resigned."

He said, though, that the city is left in capable hands with the appointment of Mike Brown.

"And with Darryl Buchanan working with Mr. Brown, it will be a good team," Pickell said.

Williamson last week dumped right-hand man Buchanan and hired Brown, who worked for the Genesee Regional Chamber of Commerce, as the new city administrator. He also appointed a new interim police chief, John Keahey, who is the third person in less than a month to fill the post.



The mayor initially won a term as mayor in 2003, and then was re-elected in 2007 in a close election against challenger Dayne Walling.



Since then, there's been a string of bad news, including budget deficits, layoffs, controversy over a proposed drag strip and turmoil at City Hall.



Williamson has pointed to some successes in the city, including the revitalization of downtown and the new alternative energy plant.



Flint voters in 2002 recalled then-Mayor Woodrow Stanley -- an election that led to a state takeover.