"We are now focused on the lessons we can learn from the incident and also what additional operational redundancies might be available," Cahill said at the cruise industry conference this week.
Another ship, the Carnival Splendor, had a fire in 2010 due to "a catastrophic failure of a diesel generator," said Cahill, the Carnival president.
Sen. Jay Rockefeller, the chairman of the Commerce, Science and Transportation Committee, sent a letter Wednesday to Micky Arison, the chief executive officer of Carnival Corp.
"The Coast Guard has responded to a string of 90 marine casualty incidents with passengers onboard Carnival ships in the last five years," the West Virginia Democrat wrote. "It seems that Carnival has failed to take any meaningful course of corrective action after these continual incidents. This needs to change."