Has Chris Christie changed his tune?

(CNN) - New Jersey Gov. Chris Christie has spoken out several times as controversy simmered, strengthened and boiled over in a very public way with a marathon news conference on Thursday. The allegation is that Christie’s aides caused a traffic jam in one city to punish its mayor, who did not endorse Christie’s re-election.

Christie has expressed a range of reactions in public as the story developed. First he joked about it. Then he said mistakes were made. On Thursday, after more details became public, he said he was humiliated, embarrassed – and very sorry for the whole mess.

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Here’s a look at what happened – and what Christie has said about it as the story developed:

WHAT HAPPENED

August 13: In e-mails that surfaced January 8, Christie’s deputy chief of staff, Bridget Anne Kelly, uses a private account to contact an official with the Port Authority of New York and New Jersey, which operates the bridge connecting the two states. “Time for some traffic problems in Fort Lee,” she writes, according to copies of the e-mails obtained by CNN. The official, a Christie political appointee named David Wildstein, writes back, “Got it.”

September 9-13: Two lanes of the bridge are closed, causing significant traffic backups. Allegations quickly begin to swirl that the closures – later attributed to a traffic study - are political payback for Fort Lee’s Democratic mayor, Mark Sokolich, declining to endorse Christie’s re-election campaign.

September 10: Fort Lee Emergency Medical Services Coordinator Paul Favia writes to the city’s mayor to highlight delays in medical care that he said were caused by unusual traffic jams on the bridge.

September 12: Sokolich writes Port Authority Deputy Executive Director Bill Baroni to complain that the closure is a political punishment, according to the Star-Ledger newspaper in Newark, New Jersey.

September 13: The Port Authority orders an end to the lane closures. Executive Director Patrick Foye says the closures didn’t follow policy and endangered public safety, the Star-Ledger reported.

HOW CHRISTIE RESPONDED

October 15: Christie doesn’t directly address the allegation but is combative when it’s brought up during his re-election campaign debate with challenger Barbara Buono. The Democratic state senator derides Christie as representing “the worst combination of bully and bossism” and brings up the lane closures as an example. Christie doesn’t talk about the bridge scandal but accuses Buono of endorsing a corrupt Democratic official. “You want to start throwing stones tonight, you better get out of your glass house,” he tells her.

WHAT HAPPENED

October 16: Foye tells reporters that a review of the closures is under way, according to the Star-Ledger.

November 27: Assemblyman John Wisniewski, chairman of the state’s Transportation, Public Works and Independent Authorities Committee, subpoenas Foye to testify at a December 9 hearing on the issue.

HOW CHRISTIE RESPONDED

December 2: The governor laughs off the brewing controversy, joking at a news conference that he was out on the bridge, adjusting traffic cones to block traffic. "I worked the cones,” he said. “Unbeknownst to anyone, I was working the cones.”

WHAT HAPPENED

December 9: Wisniewski’s committee holds its first hearing on the traffic issue. Wildstein is scheduled to testify at the hearing but resigned the week before and does not appear.
At the hearing, Foye calls the lane closings illegal and improper, according to a statement on the legislator’s website that also describes testimony by agency employees who said Wildstein told them not to tell Foye about the closures.
In a statement after the hearing, Wisniewski says the revelations reveal a “culture of fear” and “rampant dysfunction” in the Port Authority and vows further inquiry.

December 10: The Port Authority inspector general begins an investigation, according to the Star-Ledger.

December 12: Wisniewski issues additional subpoenas seeking more records from officials involved in the lane closures.

HOW CHRISTIE RESPONDED

December 13: At a news conference, Christie, sounds more subdued than in previous statements on the issue. He announces the resignation of New Jersey’s top Port Authority official. He says Baroni accepted responsibility for not following protocols in approving the lane closures and describes himself as not angry but “bothered.”
"Mistakes are made, and when mistakes are made, people have to be held accountable for them," Christie says.

At the same news conference, he denies any spat with Sokolich, saying the drama was “created and manufactured.”

"I don't have any recollection of ever having met the mayor of Fort Lee in my four years," Christie said. "He was not somebody that was on my radar screen in any way - politically, professionally, or in any other way - until these stories came out in the aftermath of the closing."

WHAT HAPPENED

January 7-8: E-mails emerge showing that Christie’s top aides were aware of plans to shut down lanes of the bridge. They garner national news coverage.

HOW CHRISTIE RESPONDED

January 7: He issues a statement saying he was misled by his staff.
"What I've seen today for the first time is unacceptable. I am outraged and deeply saddened to learn that not only was I misled by a member of my staff, but this completely inappropriate and unsanctioned conduct was made without my knowledge. One thing is clear: this type of behavior is unacceptable and I will not tolerate it because the people of New Jersey deserve better. This behavior is not representative of me or my Administration in any way, and people will be held responsible for their actions.”

Two days later – on Thursday – Christie fires Kelly, the staffer who wrote the “time for traffic problems” e-mail, and apologizes in a nationally televised news conference. “I am embarrassed and humiliated by the conduct of the some of the people on my team,” a contrite-sounding Christie says

WHAT HAPPENS NEXT

January 9: State Sen. Ray Lesniak says he will formally request an investigation into Christie’s administration over the bridge controversy.

January 9: The U.S. Attorney’s Office for the District of New Jersey announces that it is reviewing whether it should get involved. “The Port Authority Office of Inspector General has referred the matter to us, and our office is reviewing the matter to determine whether a federal law was implicated,” spokeswoman Rebekah Carmichael says.

This story is based on reporting from CNN’s Paul Steinhauser, Steve Brusk, Lindsey Knight, Steve Kastenbaum, Jonathan Auerbach, Bill Mears.