WHEN local mum Sara Persad took husband Deo, and daughters Olivia, 20, and Ebony, 10, to swim at the lagoon at Seventeen Seventy, she didn't imagine that two of them would end up in hospital.
Within 20 minutes of being in the water, Ebony and Deo had both been stung by box jellyfish.
"I thought (Ebony) had been murdered, or attacked by a shark at the least. It was just this blood-curdling scream and she tried to get back into shore," her older sister Olivia said.
"Dad ran in to grab her, and the next thing, he was covered in them too."
Mrs Persad said if it wasn't for some quick-thinking locals, the situation could have been much worse.
"It was bloody awesome to see. People were running down with cloths and vinegar, and people were calling the ambulance," she said.
"I'm pretty sure we cleaned the cafe out of vinegar."
Deo and Ebony were rushed to Bundaberg Hospital to have their stings treated.
"The pain was like being burned all over my legs and left arm," Ebony said.
Doctors told the family that box jellyfish attacks were a rarity this far south, but they also said Ebony was lucky to be alive.
"I didn't realise that they could be fatal," Mrs Persad said.
"But according to the doctor, a child only needs 10% of their body covered in stings for cardiac arrest to occur. Ebony had 6%.
"Ebony can't walk on her legs yet because they're too swollen. The two of them have to wear compression bandages for a while."
Ebony is only the second severe victim of a box jellyfish sting reported in five years in the Gladstone region
Rachael Shardlow was stung in 2010 in the Calliope River.