As in many remote Pacific nations, the island kingdom of Tonga is connected to the world by a single cable, roughly the width of a garden hose, that carries hair-thin optic fibers across a vast ocean bed.

That lone conduit is the means by which Siniva Filise, who lives in Wales and is part of the large Tongan diaspora, starts each day with a video call from her mother 10,000 miles away. "She’s like the alarm — she doesn’t care what time it is,” Filise said. "She’ll just call.”

But for the past four days, the phone has been silent. Tonga’s undersea cable was severed by a huge volcanic eruption on Saturday night, and the country now faces weeks of digital darkness as a repair ship prepares to make its way from Papua New Guinea.