Teenage Brothers from the U.S. Killed in N.Z. Volcano Eruption — and Their Parents Are Missing

A pair of U.S.-born teenage brothers have been identified as victims of the New Zealand volcano eruption, while their parents remain missing.

Matthew Hollander, 13, and Berend Hollander, 16, died in the hospital of injuries sustained in the Monday afternoon blast on White Island, the boys’ family members confirmed in a statement obtained by PEOPLE.

The boys’ parents, Martin Hollander, 48, and Barbara Hollander, 50, are still unaccounted for, according to the Chicago Tribune.

“We are absolutely heartbroken by this loss. Ben and Matthew are wonderfully kind and spirited boys who lived short but very fulsome lives,” the statement read. “They loved [their school] and all their friends, and the Australian sports and outdoor lifestyle they adopted on moving from the United States six years ago. They had a positive and lasting impact on everyone’s paths they crossed.”

Matthew and Berend, who went by Ben, were born in the Chicago area, though the family later moved to Martin’s native Australia, the Tribune reported.

“They were a great family,” Chicago neighbor Jeff Richmond told the outlet. “The boys were very nice, always active and always outdoors. They were very pleasant people.”

The boys attended Knox Grammar School in the suburbs of Sydney, and the school’s headmaster Scott James confirmed their deaths in a letter to parents obtained by PEOPLE.

Both Matthew and Ben were heavily involved in the school, and both played various sports and participated in the Australian Army Cadets, James wrote.

“Matthew had a close circle of friends and was popular amongst his peers. He was always enthusiastic about life and was actively involved in school and year group activities,” the letter read. “Ben’s engaging smile and quirky sense of humor made him a good mate to his close group of friends and a welcome member to every classroom.”

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Dad Martin’s LinkedIn page lists him as an investment director at Wipunen Incrementum Capital in Sydney.

The boys are among eight confirmed victims of the White Island eruption, though the death toll is suspected to be 16, as eight people remain missing on the island.

Australian woman Julie Richards, 47, and her 20-year-old daughter Jessica were also confirmed to have died in the blast by a family spokesperson.

A State Department official confirms to PEOPLE that U.S. citizens are among those injured and missing following the incident, but that identification of victims is still ongoing.

The U.S. Embassy in New Zealand said in a statement it was aware “of U.S. citizen casualties,” though a number remains unclear. There were nine U.S. citizens on the island when the volcano erupted.

Police said Thursday they had developed a plan to recover the bodies that are still on the island, though it remained contingent on various risks, including weather conditions.

“A lot has to go right for us tomorrow to make this work,” police said in a statement. “There is no zero risk option in regard to the plan but we have carefully considered it. We don’t expect the risk to change tonight or tomorrow but we have planned for it.”

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At least 28 patients are still being treated in six hospitals across New Zealand, and 23 are in critical condition, officials said.

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Geoff Hopkins, who was leaving the island by boat after a day of exploring with his daughter, said his vessel turned around to help victims, many of whom had suffered severe burns.

“There were 23 people that had their lives in our hands,” his daughter Lillani told Stuff. “It was probably the longest two hours of my life.”

Forty-seven people were visiting the island when the volcano erupted, and more than three dozen were traveling on Royal Caribbean’s cruise ship Ovation of the Seas.