WELLINGTON, New Zealand – A young conservation worker who was checking a volcano's crater lake when it unexpectedly burst to life, spewing mounds of ash and soot, most likely died in the eruption in the remote nature reserve, a conservation official said Saturday.
The eruption in one of Raoul Island's three main craters — the first there since 1964 — threw rocks and boulders into the air and buried the area around the lake in mud and ash up to 16 feet deep.
A rescue team was expected to set sail from New Zealand on Sunday to inspect the remote island and assess prospects for recovering the missing worker, who was part of a small team monitoring the nature reserve.
By opting for a three-day sea trip, rather than flying, officials virtually ruled out finding the worker alive.
"He was at the exact epicenter of the massive destruction," said Conservation Minister Chris Carter after speaking to a rescue worker who had witnessed the devastation.
Carter said the rescuer estimated the worker, who left an hour before the eruption for the crater lake for a routine check of the water temperature, had only a "1 to 2 percent chance" of surviving.
Two of the five surviving conservationists went in search of their missing colleague but could not get past a twisted mess of trees and mud and the erupting volcano forced them back.
All five — three men and two women — were evacuated by helicopter to Auckland.
"They were very traumatized, as one would expect. There has been only the six of them on the island since last October," Carter said. "They are like family members."
A member of the helicopter rescue mission said the group was distraught at leaving their workmate behind.
"They are clearly upset. The guy is a good friend and they're a fairly close group," senior Constable Barry Shepherd, a search and rescue expert, told reporters.
The conservation workers did not immediately speak to the media.
An aerial search for the missing man, in his early 30s, was hampered by fading light and clouds of steam and ash. The man's name was not released.
John Funnel, the helicopter pilot who flew the rescue mission, said the eruption ripped up trees and dumped ash over half the 72-acre island. He said the dense clouds of ash would have brought the helicopter down if he had flown into them.
The rescue team would have had to "get right into the vent of the volcano which was still active in order to search for the missing party," he said. "Hovering in a crater lake when it has just been erupting is not where you want to be unless you absolutely have to."
A group of police, conservation officials and one vulcanologist was likely to set sail Sunday, but will only land if they decide it is safe based on visual checks and updates on seismic activity, said Rolien Elliot, the Conservation Department's area manager.
The volcano spewed steam and ash hundreds of yards into the air on Friday, and moderate earthquakes of magnitude 3 to 4 shook the island, but no lava or molten rock was reported flowing from the vent.
Vulcanologist Michael Rosenberg said the eruption was of a "moderate size" and looked similar to the one in 1964.
Friday's explosion "seems to have occurred with no immediate warning," New Zealand's main geological group, GNS Science, said in a statement.
On Saturday, there were only clusters of small earthquakes and no obvious volcanic activity on the partly bush-covered island, GNS Science reported.
The last known eruption on Raoul Island, about 625 miles northeast of the New Zealand city of Auckland, was on Nov. 21, 1964, from a vent close to Green Lake. There were no casualties.
The chain to which it belongs — the uninhabited Kermadec Islands, governed by New Zealand — was formed by a string of volcanoes that rose up to 26,000 feet from the ocean floor.