The chilling image shows four women stranded on a rock in rapids seconds before a dam’s floodgates were opened, sweeping one of the girls to her death.
The group was reportedly seen holding selfie sticks when the five-minute warning siren for the floodgates sounded on the Waikato River in New Zealand on Monday.
As the waters started surging, three of the swimmers made it to safety on a larger rock, but Rachael Louise De Jong, 21, did not survive.
The body of the “kind and wonderful” Auckland student was recovered from a rockpool by police on Monday night.
German tourists Katrin Taylor and Kevin Kiau watched the tragedy unfold from a viewing platform on the Aratiatia Dam.
They spotted four people clinging to a submerged rock in the middle of the raging rapids after the alarm sounded.
“They were holding selfie sticks,” Taylor told Stuff.co.nz.
“We could see the water was rising further and that they were in danger of getting washed away.”
Taylor said a man helped pull two of the girls to safety on a nearby rock.
But at least one of the girls was swept into the raging torrents when the water level became too high.
“We saw the first girl made it. The guy pulled her in. The second girl jumped and made it safe as well,” Taylor said.
“The third girl, she jumped but the water was washing her away so the guy grabbed her.”
The tourists said they believed the man and girl were washed away, but he must have made it to safety.
The final girl also managed to clamber onto a larger rock.
De Jong’s death has been referred to the coroner.
Her brother Daniel penned a touching tribute to the student, saying she had an “infectious smile that could cheer anyone up.”
“Yesterday I lost one of the most important people in my life, my wonderful sister,” he wrote.
“Not only was she an inspiration to us all, she was my best friend, and the most perfect sister I could ever have asked for.”
“I can’t even begin to describe how much I’m going to miss you, and how incredibly unfair it is that you have been taken far, far too soon.”
“You never spoke a bad word of anyone, and you had such an infectious smile that could cheer anyone up.”
“There’s not enough words in the world I could use to describe you. I love you so much Rachael, rest easy.”
Power authorities open the Aratiatia Dam floodgates upstream several times a day.
A warning siren sounds before the water is released and there are signs alerting people to the danger and telling them not to swim there.
Mercury Energy, which owns and operates the dam, said it is reviewing its safety procedures in the wake of the tragedy.
Chief executive Fraser Whineray said: “Our sincere thoughts go out to the family and friends of the person who has passed and to those who are recovering at the local hospital and who will be traumatized.”