Passengers were evacuated to shore and allowed to re-board Monday evening.
Carnival Cruise Line said all hotel services including air conditioning, elevators, toilets and galleys are fully functional and the normal activities, entertainment, dining and programming are being offered.
Carnival Liberty remains alongside at St. Thomas while technical experts conduct an assessment of the affected engine area and determine what caused the fire. Among them are USCG marine safety investigators and inspectors from Marine Safety Detachment St. Thomas.
Passengers are able to spend the day ashore if they wish and the company is providing free shuttle service to popular areas on the island along with a $150 per person shipboard credit.
USCG said watchstanders at the Coast Guard Sector San Juan command center received a report from Carnival Liberty of a fire at approximately 11:45 a.m. Monday.
Carnival Liberty had just begun a seven-day cruise from San Juan and is carrying 3,346 passengers and 1,150 crew.
The 110,000gt vessel was built in 2005 and extensively refurbished in 2011 as the first in the fleet to add Fun Ship 2.0 dining and entertainment enhancements.