A Carnival Corp. ship had the biggest coronavirus outbreak in the industry. Now Congress is probing the company.

Carnival, the world's largest cruise company, has experienced several high-profile outbreaks on its ships; at least 55 passengers or crew members who sailed on the fleet have died, a Washington Post review found.

In a letter dated Friday, the U.S. House Committee on Transportation and Infrastructure requested that the company hand over records including a copy of plans to prevent or respond to infectious diseases, including covid-19; any official documents or other communication referring to the novel coronavirus at the company's headquarters or on its ships; correspondence about the virus between any shipboard employee and several federal and state authorities, including the Centers for Disease Control and Prevention; and any communication between headquarters and ships that reference covid-19.

"Our committee, the U.S. Congress, and the American public need to be assured that the global cruise line industry, and Carnival Corporation . . . in particular, are instituting necessary measures to ensure that the safety of the traveling public and crew members will be your number one priority when your ships set sail again," says the letter, signed by U.S. representatives Peter DeFazio, D-Ore., and Sean Maloney, D-N.Y.

The committee wants all records dating to Jan. 1 and has given the company until May 15 to start complying. It also requested records pertaining to communications with Carnival from the CDC and U.S. Coast Guard.

The letter, addressed to Carnival CEO Arnold Donald, emphasizes the vulnerability of cruise ships to coronavirus, calling them "a fertile breeding ground for infectious diseases." Donald has argued that cruise ships are not riskier than land-based activities, a contention that health authorities dispute. He and others in the industry have also insisted that cruise ships are not to blame for spreading the virus, but are subject to more stringent reporting requirements that cast a unique spotlight on cruising.

"Our goal is the same as the committee's goal: to protect the health, safety and well-being of our guests and crew, along with compliance and environmental protection," said Carnival's chief communications officer, Roger Frizzell, in a statement. "We are reviewing the letter and will fully cooperate with the committee." 

Cruise lines voluntarily stopped sailing in March, the day before the CDC issued a no-sail order. The agency extended the order last month for at least 100 days.

Carnival isn't the only cruise operator to struggle with the virus, though the company's sheer size means it has seen a larger proportion of cases. The Washington Post tally found that the virus infected people on at least 55 ships across the industry and killed at least 65.

In the letter, the committee pointed out the discrepancy between the seriousness of the pandemic and the images that Carnival's cruise lines - which include Princess Cruises, Holland America Line, Carnival Cruise Line and Costa Cruises - use to attract customers.

"While cruises are often viewed as a care-free escape from reality where passengers can dine, dance, relax, and mingle, we would hope that the reality of the covid-19 pandemic will place a renewed emphasis on public health and passengers safety, but frankly that has not been seen up to this point," the letter says, noting the company's front-facing websites. "In fact, it seems as though Carnival Corporation and its portfolio of nine cruise lines, which represent 109 cruise ships, is still trying to sell this cruise line fantasy and ignoring the public health threat posed by coronavirus to potential future passengers and crew."