Tonga is experiencing a near total blackout of mobile and internet services after the country's only undersea cable was damaged.
The problem took the island nation of about 100,000 people by surprise on Sunday night. Bad weather is being blamed as the cause of the fault.
A satellite link is providing limited bandwidth but officials say they may have to restrict social media use.
Residents have been told fixing the problem could take several weeks.
Blocking Facebook and YouTube?
Tonga Cable said in a statement the fault occurred at 8:45pm local time (7:45 GMT) on Sunday and cites a "magnetic storm" and "lightening" as causes.
A repair vessel is currently docked in Samoa and could be in Tonga within three days. The restoration work would then take one or two weeks, the company said.
In the worst case scenario, it said fixing the 827km (514-mile) cable linking Tonga and Fiji could take up to three weeks.
"We've been informed that 80% of our international traffic is from social media," Tonga Cable director Paula Piukala told Radio New Zealand.
"We may block Facebook, YouTube and stuff like that in the meantime so that we can maximise the small bandwidth that we have from satellite on what is important to the country."
'No plan B'
"It's a reality check - people suddenly realise how dependent they've become on the internet and how much is linked to the web working," Mary Lyn Fonua, editor of the online news service Matangi Tonga, told the BBC.
There's been no email, no money transfers and companies are affected from things to flight bookings to simple card terminals in supermarkets.
"I went to the supermarket and couldn't pay with my card," she said. "So I had to run over to an ATM and get some cash - fortunately the ATM still worked."
Banks and government agencies have their own satellite links, she explained, and have managed to stay largely operational during the past few days.
But companies like airlines have to make all bookings manually. Tonga's population of about 100,000 people is spread over more than 30 islands.
"It took everyone by complete surprise and there was no plan B," Ms Fonua said.
"At the office, we have to wait for 30 minutes for our inbox to load, then another 15 minutes to open an email. And we haven't been able to send a single reply so far."