SYDNEY, Australia — When the Hunga Tonga-Hunga Ha’apai volcano erupted with colossal force at 5:10 p.m. local time on Saturday, Jan. 15, Soane Francis Siua, a Catholic seminary student in Fiji, heard a loud boom and tried to work out why the earth seemed to be rattling.
Thunderstorm? Earthquake? Cyclone? No, he quickly discovered: It was a volcano not far offshore from where he grew up in Tonga. He remembered being home when it erupted a few years ago. This time, based on what he could feel from 400 miles away, he suspected something far worse.
He called his mother on the main island, Tongatapu. She answered, offering a few details from a frightening scene. A tsunami warning. Thick clouds. A storm of black rocks pelting buildings, bouncing off cars like marbles on tile.
“It was all falling from the sky, and it freaked her out,” he said. “It was the first time she’d ever seen anything like that.”
Trying to keep calm, he promised to call again after relaying the news to his sisters in the United States. But that was it. He couldn’t get through to his mother again for almost a week.
It was the same for tens of thousands of Tongans who live outside the remote Pacific kingdom. For about an hour, hints of what had been wrought by the world’s largest volcanic eruption in decades trickled out through phone calls and videos posted to social media. Then the lone undersea cable connecting Tonga to the world snapped, severed in the violent upheaval.
And with that came the disconnection that has defined the disaster so far. Even as the eruption’s scale spread far and wide — with a sonic boom heard as far away as Alaska, and surging surf killing two people and causing an oil spill in Peru — the human impact closest to the blast seemed to fade from view, defying the expectations of a hyper-connected age.
While the rest of the world was left to gawk and worry at the sight of a 300-mile-wide volcanic mushroom cloud captured by distant satellites, in Tonga there was barely any communication, just the visceral experience itself of the volcano and the tsunami that followed.
“I’ve dealt with a lot of these kinds of crises,” said Jonathan Veitch, the United Nations coordinator based in Fiji, who noted that it usually took a half-hour to account for U.N. staff after a diaster but took a full day in Tonga. “This one is a bit different.”
A week later, what happened on the ground is only just now coming into view, mostly through clipped conversations over satellite phones dependent on clear skies. The portrait so far is a blurry landscape of destroyed property, narrow escapes and a bit-by-bit local cleanup, but it is clear that the human toll has yet to match the worst fears of people like Mr. Siua.
So far, only three deaths have been reported. The most immediate worries concern drinking water tainted by ash and the risk of aid deliveries — which began on Thursday — bringing Covid to a country that is coronavirus free after locking its borders when the pandemic began.
But more than a week after the volcano erupted, the process of fully assessing the damage, never mind responding, is still moving with a pace from a pre-Internet age.
As of Thursday, at least 10 sparsely populated islands where buildings appeared to have been damaged had yet to be checked by the Tongan Navy or any other agency, while at least one aid flight from Australia had been turned back because of a positive Covid case on board.
The challenge, perhaps, cannot be separated from geography. Tonga, a nation of about 170 islands that are roughly 1,400 miles northwest of New Zealand (and 3,000 miles from Hawaii) has always been hard to reach. It was first inhabited around 3,000 years ago, giving it a much shorter human history than Australia or other countries in the Asia-Pacific region.
While celebrated for its white sand beaches, the archipelago is also vulnerable to a wide range of disasters. Climate change has brought rising seas to low-lying atolls. Cyclones and powerful storms have been tearing through the area more frequently and with greater strength as the planet warms.
And that’s all on top of what can be found below: Tonga sits along the so-called Ring of Fire, where tectonic plates grind their way into earthquakes and islands that are still rising from the deep alongside deadly active volcanoes.
Hunga Tonga has been a source of simmering fear for years. And it had been rumbling for weeks. The volcano sent up steam plumes and gases on Dec. 29 and 30, and again on Jan. 13.
“In 20/20 hindsight, these events were pointing to increasing gas pressures in the upper part of the volcano,” said Shane Cronin, a volcanologist at the University of Auckland in New Zealand.
In Tonga, where a new government had been elected in November, the eruptions led to warnings — be prepared. Mr. Siua, 24, said his mother, who lives inland, stocked up on food and water. Other people did the same.
The eruption nonetheless came as a surprise. The sound on Saturday was deafening and dizzying. Many people in Tonga have told relatives that it felt like a bomb went off right next to them, and then kept going off again and again.
“The first eruption, it was a big explosion,” Kofeola Marian Kupu, 40, a radio journalist in the capital, Nuku’alofa, said in an interview by phone. “Our ears started ringing. We couldn’t hear anything.”
Like many others, though, Ms. Kupu knew exactly what to do: flee.
With her mother, her husband, their three children and three of their cousins, they grabbed what they could and rushed for higher ground.
“We knew it was a live volcano erupting — we’d been warned,” she said. “When the explosion came, everyone just ran because they were expecting a tsunami.”
The hurling up of magma from below sent a cloud of debris nearly 20 miles into the sky. Within a few minutes, rocks started falling with a pitter-patter that sounded like very heavy rain.
A thick coating of ash followed. Then came powerful waves. Scientists predicted that the swell heading for Tongatapu, where about three-quarters of Tonga’s 100,000 people live, would rise to around four feet. Early videos from the capital before the internet cut out about 6:40 p.m. showed a steady flow of water flooding roads and ripping down fences as cars rushed away.
Tongan officials later said that smaller, low-lying islands closer to the volcano saw tsunami waves of up to 15 feet, maybe more.
The waves swept away at least three people, including Angela Glover, who was originally from England. She had moved to Tonga and opened an animal shelter with her husband, a tattoo artist. After the volcano erupted, she posted a photo of a red, glorious sunset on Instagram, telling her followers that “everything’s fine.” But when she returned to save some of the dogs she was caring for, she drowned.
Her husband, who found her body a few days later, survived by holding on to a tree. Many others clambered up and did the same. Tricia Emberson, 56, said that her uncle and his son, who live on a small island near Tongatapu that was overrun with water, also climbed into the trees for safety.
“The island was submerged or partially submerged, and pretty much everything was washed away,” she said.
The Pangaimotu Island Resort, which her uncle has run for decades, appeared to be gone. Her own home, he told her in a phone call that went through at 4 a.m. on Thursday only after dozens of redial attempts, had the entire back wall pushed into the sea.
“You grow up with this,” she said in an interview from Australia, where she has been living since just before Covid led to closed international borders. “You don’t really know the scale of these things, but you grow up with this gut instinct of what to do, and I think the evidence of that is the fact that so far we have had so few deaths.”
Many Tongans overseas who have managed to speak to their relatives — usually in the wee hours, when there was less demand on satellite service — reported that their anxious calls had been answered mostly with humble pleas not to worry. Tongans are well known for their relaxed, easygoing culture and their Christian faith, which has seemed to clash at times with the anxiety of the always-connected world.
Miti Cummings, who lives in New Zealand, said she had been calling her mother and stepfather nonstop all week in Tonga, hardly sleeping, randomly dialing their number and hoping that for some reason it would get through.
When she finally did talk to them, she said they were being “typical Tongans.”
“They just said, ‘Oh, it’s OK, don’t worry about us, look after yourself. We’ll be fine, we’re staying inside because the ash is really bad.’”
“It was such a relief,” she added — until she hung up just after 4 a.m. and realized all that she had failed to ask.
“I don’t even know if their house is still standing,” she said.
Mr. Siua, 24, the seminary student, said that when he, too, finally reached his mother at the end of the week, and connected her right away with his sisters, he also ended the call without a full picture.
He was relieved to discover that his cousins had been checking on his mother, who lives alone, but that got him thinking about his aunts and uncles on the island of Atatā.
No one had heard from their relatives there. All he knew was that in photos taken from above after the blast, not much seemed to be left: Just empty lots in the trees and a few buildings were visible. Everything was covered in the gray-brown dust of Hunga Tonga-Hunga Ha’apai.
Yan Zhuang contributed reporting.