Ovation of the Seas passenger Sylvain Plasse was hiking down the side of Mount Maunganui in New Zealand during a port stop in Tauranga when he saw plumes of smoke rising off White Island. It must be industrial, he thought. 

Plasse, an actor from Toronto, then ran into a jogger at the base who told him it was a volcanic eruption. He thought it was his lucky day. He was witnessing a spectacular natural event.

But things quickly turned nightmarish. 

He returned to the Royal Caribbean ship to find out that there had been a tour to White Island that day.

"The excitement turned into horror," he told USA TODAY.

Eighteen people were killed, including two whose bodies were washed out to sea and may never be found, authorities said Wednesday. Two teen brothers from Chicago were among the victims. More than two dozen had severe burns.

Forty-seven people were on the island at the time of the eruption. Many were from the Royal Caribbean cruise ship that had left Sydney two days earlier. 

Plasse, who has been on 105 cruises with Royal Caribbean, had met newlywed couple Lauren and Matt Urey the night before, and they had told him they were planning to take a fun excursion the next day. His mind flashed to them immediately.

Ryan Rogers, from Austin, Texas, was on the cruise with his mother to celebrate her 80th birthday.

"People were very concerned," Rogers said. "Their lives just changed in the blink of an eye."

After the Dec. 9 eruption, Rogers said that passengers received "little to no" updates from Royal Caribbean. 

"Only (from) the captain via loudspeaker three times over two days, then nothing ever was said," Rogers said. Eventually, they received a revised itinerary in their stateroom and one day's refund for the interruption in the trip.

The cruise remained in port in Tauranga as local authorities investigated after the eruption, according to a copy of the updated itinerary obtained by USA TODAY.

"Royal Caribbean was very hush hush about the situation and wouldn’t divulge any info," Rogers said.

Passenger Steven Angie Ward also said information was scarce. He told The Daily Mail that passengers were relying on news outlets rather than the cruise line.

Passengers Sophie Mcilquham and Toni Raponi echoed Ward and Rogers. 

"Until we turned on the TV we would have had no clue what had happened," Mcilquham told The Daily Mail. She said the crew originally referred to the eruption as an "incident." And Raponi said that others "back in Australia" knew more than the passengers onboard.

Plasse, however, thought the cruise line did everything it could for the passengers. "He was waiting to get more info probably," he said of the ship's captain. He also said that Royal Caribbean offered counselors onboard.

On Dec. 11, the ship departed from Tauranga, according to the itinerary, and sailed to Wellington, New Zealand, to Picton, New Zealand and spent the weekend cruising before arriving in Sydney, Australia on Monday morning. 

Though the cruise sailed on, it was over, in a way, for the remaining passengers. 

"Witness something like this when some guests have lost their lives," Plasse said. "It’s traumatic. People cannot even imagine this."

The mood for the remainder of the cruise was somber.

"We were in a pretty blah mood the rest of the trip and wanted to just get off the ship," Rogers said. "We felt so bad for all the passengers and crew affected. It’s really tragic." 

Jonathon Fishman, spokesman for Royal Caribbean, told USA TODAY in an email that the cruise line is offering support and services to those affected. They are working to help guests and the authorities, he said.

"Our foremost focus remains to support the impacted guests and their families and helping them in every way possible," Fishman added.

Now though, as a result of the eruption, Royal Caribbean is also making a change to their expedition offerings, at least temporarily.

"After this heartbreaking incident, we are suspending tours of active volcanoes," Fishman said. 

'It's a risk': Questions about volcano tourism safety arise after New Zealand eruption

Why were tourists on the island?

That's the question police will be investigating after increases in seismic activity had been recorded on White Island for weeks.

"These questions must be asked and they must be answered," Prime Minister Jacinda Ardern said in Parliament.

GeoNet, which tracks New Zealand's seismic and volcanic activity, raised its alert level on the island in November after increasing sulfur dioxide gas. Volcanic tremor also increased, and the agency wrote at the time that the island "may be entering a period where eruptive activity is more likely than normal."

So who is responsible for cruisers?

Jeff Ment, a travel industry attorney at Ment Law Group, told USA TODAY that a cruise line's responsibility is typically contingent on the partnerships they engage in. Are cruise lines liable for injuries to passengers? 

"Cruise lines have to partner with reasonable vendors because they don’t have any specific knowledge about volcano eruption or volcanic conditions of New Zealand," Ment said. "They're in the business of running a cruise line."

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Contributing: Leora Arnowitz, John Bacon, Ryan W. Miller

This article originally appeared on USA TODAY: New Zealand volcano eruption: Royal Caribbean cruise details emerge