United States (AP)— Many people whose loved ones stayed behind in the pathway of Hurricane Ian are crowdsourcing rescue efforts as they grapple with the helplessness of waiting and not knowing.

In TikTok videos and Facebook posts, families are sharing their desperate pleas and strangers are answering their calls, even as local officials urge people to use official channels for help.

Hannah Foltz had assumed her grandparents, Janet and Larry, evacuated from their mobile home in Naples. But when the 35-year-old in Indiana heard from her mother, she learned they had not only stayed but the water that flooded their home was almost chest deep with the fridge floating. Her 75-year-old grandmother didn’t know how to swim.

“We were all in like pure panic mode, sitting in Indiana, crying, feeling helpless,” Foltz said.

She turned to a Facebook group of more than 400,000 people, #HurricaneStrong.

“They are terrified, and both have health conditions,” she posted in the group along with her grandparents’ address.

She didn’t expect for even one social media user to head out to her grandparents and report back so quickly. But that was followed by another good Samaritan and then two more.

“Knowing that there are people out there that just literally want to go help a complete stranger,” she said. “That was just like a miracle.”

An informal digital structure built on the backs of previous disasters was on full display in the midst of Ian’s fury. Users shared online forms to request and volunteer for rescues. Facebook groups sprung up with pleas for help, including phone numbers and addresses, and offers from volunteers to step in.

Authorities continue to urge Floridians to use official emergency channels, like 911, to report immediate distress, not social media, which can be unreliable and even put the good Samaritans who respond in danger. US Coast Guard spokesman Erik Villa said that family members should try to get a hold of their loved ones and monitor the area they live in before calling emergency services.

Kingman Schuldt, greater Naples retired fire chief with the International Association of Fire Chiefs, said social media users should also be discreet with how much public information they share about their loved ones online.

“Obviously, when you put a public request for help you have to be careful with how much you put out there because there are bad actors,” he said.

The posts are pulling on heartstrings and driving some to rush in to help.

There was a brief moment Wednesday when Heather Donlan’s 87-year-old father, Jack, called his daughter for what he thought would be the last time. A pipe had burst in his Naples home and water was coming in from the outside — sealing him inside.

Donlan, whose Naples home was also taking on water, had already dialed 911 about her dad and was told that rescuers would try to get to him, but the roads were impassable. There was no way she could reach him herself.

A firefighter friend recommended she share her post on Facebook and see if anyone in the area could come to her father’s aid. Her father had already been in the water for hours and his phone was losing battery.

A local teacher and her sons walked through the water to get to Donlan’s dad. They drove him to Donlan’s home three miles away, and he was taken to the hospital for dehydration and a wound on his ankle.

“That social media post 100 per cent saved his life,” the 48-year-old Donlan said. “The people here on the ground wouldn’t have been able to help if it had not also been for the people willing to re-share, push and post when we didn’t have service.”