They began evacuating sick passengers, but two passengers had already died on board from coronavirus, Miami-Dade Mayor Carlos Gimenez.
"I want to offer my condolences to the families of the loved ones of the two people who died from Covid-19 on that ship. It is heartbreaking news," Gimenez said Saturday.
"Our hearts go out to their family, friends and all who are impacted by this loss," the cruise line said in a statement released to news media on Saturday. CNN has reached out for comment following the third death but has not yet heard back.
The third passenger from the Coral Princess cruise ship died after being transported by a private ambulance to a hospital in Hialeah, Florida, late Saturday night, according to a news release from Gimenez's office on Sunday.
Five other passengers were transported from the ship prior to the death. Two of them were taken to Larkin Hospital by ambulance in critical condition while three others were taken to Tampa to receive treatment in a hospital, the release said.
The ship spent nearly a month at sea
Medical staff sent to help the ship
It was announced Saturday that while the most serious cases would be taken to the hospital, some passengers would remain on the ship to receive medical treatment.
On Sunday, Mayor Gimenez sent medical staff, including a doctor and nurses to the ship to help.
Eight more passengers were taken to local hospitals in unknown condition, according to the release.
The county also replaced the ship's oxygen cylinders with full ones after learning the supply on board was critically low, the release said.
The ship is required to report passenger condition information to federal agencies including the Centers for Disease Control and Prevention, Customs and Border Protection and the United States Coast Guard, in order to have passengers offloaded, the release said.
On Saturday, Princess Cruises said in a statement that healthy passengers cleared to leave the ship would be disembarked and flown back to their homes.
However, the process of disembarking and flying out could take several days, the statement said.