A cruise ship employee was burned in a generator fire that broke out following an explosion on board early Wednesday morning, officials said. The ship — American Queen Voyages' Ocean Navigator — was docked at a pier in Portland, Maine, when the incident happened, leaving the crew member with serious injuries and launching an investigation into the cause.

Firefighters with the Portland Fire Department responded before 7:30 a.m. EDT on Wednesday to reports of smoke in the engine room of the Ocean Navigator, a visiting cruise ship, the city of Portland said in a news release. The fire department received additional reports indicating that an explosion may have broken out inside the engine room and suggesting it could be related to a generator on board the ship. 

Fire officials also received word before arriving at the scene that one member of the Navigator crew had been burned. They treated the crew member who had been burned before arranging transport to a nearby hospital, Portland officials said. The crew member was seriously injured, but the injuries were not considered life-threatening.

The ship was carrying 128 passengers, most of whom were sightseeing on land Wednesday, in addition to 82 crew members, according to Portland officials and the U.S. Coast Guard. Both said the crew member who suffered burns was the only person injured in the fire.

All passengers and remaining members of the Ocean Navigator crew were accounted for. Guests are currently being housed at a local hotel, according to the city.

"The Coast Guard prevention and response team reported to the site as well as the ATF, Maine State Fire Marshall, Maine State Fire Investigator, Portland Fire Department and Customs and Border Patrol," a Coast Guard spokesperson said in a statement to CBS News on Wednesday afternoon. 

The statement went on to note that the the fire happened "in the engine room on a generator" and added that the exact cause of the fire was still under investigation. The Coast Guard was working to determine if the Ocean Navigator could continue to be "seaworthy" as crews ventilated it after the fact, CBS affiliate WGME reported. 

"Additional crews were simultaneously able to stabilize the engine room issue and remained on scene to assist with extensive ventilation efforts and complete overhaul to prevent any further issues," the city of Portland said Wednesday. 

In:
• Cruise Ship
• Fire
• Explosion
• Maine