A Viking cruise ship needed to be evacuated over the weekend as engine trouble and stormy weather caused the ship to take on water and endanger the 1,373 passengers and crew aboard. What played out was a chaotic 48-hour nightmare.
All the important details have yet to emerge about what happened on the Viking Sky cruise ship that carried 1,373 passengers and crew, like why the ship was traveling in dangerous weather, and Norway officials have begun investigating. We now know that low oil levels caused the engine to fail.
Here's everything we know so far about the Viking Sky cruise incident:
What was the Viking Sky's plan?
The Viking Sky, a vessel with gross tonnage of 47,800, was on a 12-day trip that began March 14 in the western Norwegian city of Bergen, according to cruisemapper.com.
The ship was visiting the Norwegian towns and cities of Narvik, Alta, Tromso, Bodo and Stavanger before its scheduled arrival Tuesday in the London-area port of Tilbury on the River Thames.
The ship started listing dangerously
The Viking Sky sailed from the northern city of Tromso bound over the weekend for Stavanger in southern Norway when the ship began struggling with engine failure, started listing dangerously, then took in water. Norwegian media reported gusts up to 43 mph and waves over 26 feet.
According to a crew member's account, exclusive to USA TODAY, the ship's four engines began shutting down in the midst of a storm that started late Friday. .
The crew member requested anonymity because he was not authorized to speak publicly.
More on our exclusive: Crew member recounts what happened on that stranded, storm-tossed Viking Sky cruise ship
The crisis began Saturday morning. As the ship drifted without power, the crew threw out anchors to keep it in place, fearing it would be smashed on treacherous offshore rocks. The crew member said the ship started to list, and the crew rushed to grab life jackets and distribute them to the passengers, some of them elderly.
Cellphone footage from the ship shows furniture sliding across rooms as the boat rocks.
"Everything was broken: plates, glasses, furniture," the crew member said. He said he saw a heavy grand piano go flying upside down inside a lounge.
Carolyn Savikas of Pennsylvania described the terror aboard the Viking Sky to Norway's VG newspaper, saying she heard a "terrible crash," after which the ship rocked, and water raced in.
"We were in the restaurant when a really huge wave came and shattered a door and flooded the entire restaurant," she said. "All I saw were bones, arms, water and tables. It was like the Titanic – just like the pictures you have seen from the Titanic."
Although the crew member described the crew as well-trained for emergencies, he said he called his family at one point when the Wi-Fi was working "to say goodbye. I was thinking it was going to sink when we listed."
What first reports looked like: Cruise ship off Norway issues mayday, begins evacuating 1,300 passengers and crew
Passengers took to social media and have given interviews about what they were witnessing onboard as they waited to be rescued.
Alexus Sheppard posted a video on Twitter of severe tilting due to the rough waters. "We're waiting for evacuation by helicopter," she wrote with the hashtags #VikingSky and #Mayday.
"You could feel the ship climbing the waves and then just plummeting on the other side. Waves were rocking the sides of the ship too, and it was kind of pitching back and forth as well," Jamey Kennedy, 64, of Clinton, Tennessee, said.
How the Viking Sky rescue mission developed
After the order to evacuate came, rescuers worked all night Saturday and into Sunday to airlift more than 400 passengers (about half the total) to shore by a fleet of five helicopters flying in the dark, slowly winching people up one-by-one from the heaving ship as the waves crashed and the winds shrieked.
Despite the danger, the crew member said some passengers rushed to be airlifted, fearing the ship would sink before rescue.
To get to the life jackets, the crew member said employees had to open doors onto open decks and into the wind and form human chains to distribute the life jackets while the ship was leaning perilously close to the frigid water below.
Those involved in the rescue mission hadn't experienced a rescue this intense before.
The CHC, a helicopter service, was called to assist the rescue effort at 2 p.m. local time on Saturday. The company's mission involved 12 pilots, seven rescue swimmers, six hoist operators, two ground support engineers and a system operator.
Its first helicopter arrived within 30 minutes after being called, and a second one later joined to assist.
"The two helicopters worked seamlessly together in a rescue pattern that ensured one aircraft was hoisting passengers at all times," according to a post on CHC's website. "During each mission, 15 to 20 passengers were hoisted and subsequently transported to safety." Two more CHC aircraft were later sent to support the evacuations, and a fifth government-contracted aircraft arrived, as well. A total of 464 passengers were lifted off the cruise ship, per CHC's latest numbers.
Ship makes it to safety
The ship, aided by tow vessels, finally limped into the Norwegian port of Molde on Sunday, freeing the remaining 436 passengers and crew of 458.
"All passengers and crew are safe, and passengers will be flying home starting tonight," the cruise line said in a statement on its website Sunday at 4:30 p.m. Norwegian time. "Throughout all of this, our first priority was for the safety and well-being of our passengers and our crew. We would like to thank the Norwegian Redningssentral and the Norwegian emergency services for their support and skill displayed in managing the situation in very challenging weather conditions."
“When we got the engine running again, we realized we were going to save ourselves," Inge Lockert, a Norwegian pilot on the ship, told the Vesteraalen newspaper.
Lockert was one of two pilots from the Norwegian Coastal Administration who boarded the ship on Saturday to help the crew take the ship into port, the Vesteraalen daily said. Only Lockert has spoken publicly.
More from the pilot: Viking Sky cruise ship woes off Norway started with engine snags, pilot says
The Viking Sky investigation begins; why the engine failed
Norwegian authorities on Monday began investigating why the cruise ship was sailing in stormy weather.
"We don't know the reason why the ship sailed, knowing such bad weather was forecast," Kurt Olsen, acting director for Norway's Accident Investigations Board, told USA TODAY. "We have a very good weather service in this country, so I would guess the crew knew everything about the forecast. How they responded will definitely be part of the investigation."
Lars Alvestad, the head of Norway's Maritime Authority, said Wednesday that low oil levels were the "direct cause" of the engine failure that stranded the Viking Sky on Saturday.
The NMA indicated in a press release that while oil in the tanks was relatively low, it was within set limits. But as the ship crossed rocky seas, movement of oil in the tanks triggered an alarm.
Olsen would not speculate why the Viking Sky captain decided to sail despite the weather warning. He said ship operations were one part of the investigation, along with a technical study of why the engines failed and a third review of how the rescue was handled.
The ultimate question: Norway wants to know why cruise ship sailed in stormy weather, forcing air evacuation
Yngve Skovly, a police inspector in the Molde region, told the Verdens Gang tabloid there was no suspicion of criminal behavior and the ship was too new to suspect maintenance problems. He said crucial information could be obtained from the ship's computer logs.
Torstein Hagen, chairman of ship owner Viking Ocean Cruises, said his company would conduct its own investigation and support government agencies reviewing the mishap. Police expected all passengers to be flown out of Norway by Monday night.
"The last few days have been both dramatic and hectic for guests and crew on board Viking Sky," Hagen said in the statement. "I would like to apologize for all our guests have been through."
A total of 36 people were admitted in local hospitals and as of Tuesday, one person was in critical but stable condition in an intensive care ward. Seven others were expected to be discharged later Tuesday, hospital officials said.
Despite the Viking Sky incident, cruising is one of the safest ways to travel, according to the trade group Cruise Lines International Association (CLIA).
Citing a 2017 study, CLIA says that although the cruise industry's capacity has grown by 48 percent, the overall number of operational incidents has declined by 38 percent.
Contributing: Sara Moniuszko, John Bacon, Maria Puente, Julia Thompson, Brittany Crocker (Knoxville News Sentinel) and Associated Press
This article originally appeared on USA TODAY: Viking Sky cruise timeline: A breakdown of what we know happened