(CNN) -- 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, said he fired a senior aide at the center of the scandal involving 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 a news conference about the orchestration of traffic jams near the George Washington Bridge through a transportation agency.
Christie gave anyone with knowledge of the incident that affected Fort Lee, 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.
Earlier, a state senator called for a federal investigation into Christie's administration over the allegations that rocked Trenton on Wednesday with the release of explosive e-mails involving political appointees in the state.
September lane closures near the world's busiest bridge connecting New Jersey to Manhattan snarled traffic for days in Fort Lee -- an event that was not only inconvenient but also potentially delayed emergency services, endangering people's lives, New Jersey state Sen. Ray Lesniak told CNN's "New Day."
Separately, Justice Department prosecutors are looking into the matter, a spokeswoman for the U.S. Attorney's Office in New Jersey said.
Christie said he was "blindsided" by the release of the e-mails and text messages that bolstered claims by Democrats that the traffic jams 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."
Fort Lee officials said that an elderly woman who suffered a heart attack died after paramedics were delayed in reaching her because of traffic problems. Details of the woman's death haven't been released, but Lesniak suggested Thursday that the issue should be part of the investigation.
Lesniak called for an investigation hours earlier on his Twitter account.
"Wow! Time for a federal grand jury. This smells of corrupt use of government authority at the highest levels," he tweeted.
Separately, U.S. Sen. Jay Rockefeller, chairman of the Senate Commerce Committee, which oversees the Port Authority, indicated his desire for an investigation in December. He asked Transportation Secretary Anthony Foxx to review the incident.