The Republican apologized repeatedly for his office's connection to the shutting down of local lanes on the George Washington Bridge in September, apparently to punish a mayor who refused to endorse Christie's successful re-election bid.
The lane closure caused massive traffic jams that for four days trapped commuters and schoolchildren in hours-long delays on the bridge.
Christie insisted that he was completely unaware of the move until Wednesday, when emails between his senior staff and an official with the authority responsible for the bridge were leaked to the press.
"I had no knowledge or involvement in this issue, in its planning or its execution," a chastened Christie told reporters.
"I am embarrassed and humiliated by the conduct of some of the people on my team," singling out his deputy chief of staff, Bridget Anne Kelly.
"I've terminated the employment of Bridget Kelly, effective immediately. I terminated her employment because she lied to me," Christie said.
The governor, whose office is bracing for an investigation by the US attorney in New Jersey, also said he would travel later Thursday to Fort Lee to apologize "face to face" to its Democratic mayor Mark Sokolich, who apparently drew the wrath of Christie aides over his refusal to back the governor last year.
Christie said he felt "blindsided" Wednesday when he learned of the communications between Kelly and a top Christie appointee to the Port Authority of New York and New Jersey, David Wildstein.
"Time for some traffic problems in Fort Lee," Kelly wrote to Wildstein, a high school friend of Christie, on August 13.
"Got it," Wildstein replied.
The Fort Lee mayor was not advised the lanes would be closed for what was said to be part of a traffic study.
Then on September 10, Wildstein texted Kelly: "Is it wrong that I am smiling?"
"No," she replied.
The brouhaha has much of New Jersey fuming, and political watchers wondering whether the Republican Party has just lost its potential number one contender for the White House in the post-Obama era.
Christie also ordered his two-time campaign manager, Bill Stepien, removed from the running to lead New Jersey's Republican Party.