New Jersey Gov. Chris Christie on Thursday said he was "embarrassed and humiliated" by the conduct of "some people on my team" over an unfolding political scandal, saying he knew nothing of their activities to apparently punish a local mayor by creating traffic jams in and around his community.

Christie, who apologized to the town of Fort Lee and the residents of the state at a nearly two-hour news conference in Trenton, said he fired a senior aide at the center of the uproar involving the alleged abuse of authority that political commentators suggest could mean bigger problems for the potential Republican presidential candidate in 2016.

"I am stunned by the abject stupidity that was shown here regardless of what the facts ultimately uncover. This was handled in a callous and indifferent way," he told reporters the orchestration of traffic jams near the George Washington Bridge through a transportation agency, the Port Authority of New York and New Jersey.

Christie told anyone with knowledge of the incident -- which exploded with the release of e-mails between certain top aides on Wednesday -- that affected Fort Lee residents, commuters, and apparently public safety over several days in September to come forward with information.

"I am responsible for what happens under my watch -- the good and the bad," he said.

But the governor said he had no knowledge or involvement of this issue in its planning and its execution.

"I knew nothing about this," he told a news conference.

He said he was "digging in" and asking questions to find out what occurred.

On the bridge: 'Those days... like a disaster'

ustice Department prosecutors are looking into the matter, a spokeswoman for the U.S. Attorney's Office in New Jersey said.

"I have absolutely nothing to hide," Christie, a former prosecutor himself, said of the pending investigation.

Christie said he was "blindsided" by the release of the e-mails and text messages that bolstered claims by Democrats that the traffic jams between September 9-13 were meant to punish Fort Lee Mayor Mark Sokolich, a Democrat who did not endorse Christie's reelection campaign.

Christie and his staff originally blamed the closures and the traffic delays on a mishandled traffic study, something he reiterated at his news conference.

He said he didn't know if it was "a traffic study that morphed into a political vendetta or a political vendetta that morphed into a traffic study."

The incident inconvenienced motorists, but also affected public safety, Fort Lee officials said.

The emergency services chief in the town referred to one case in a letter to the mayor obtained by CNN involving paramedics who were delayed in reaching an elderly woman who had suffered a heart attack. She was reached by an ambulance but later died. Further details of the woman's death haven't been released.