Around 6:21 p.m., officials received reports of children going into the river near the off-ramp in the park.
Passaic Mayor Hector Lora said an 11-year-old girl was accounted for and out of the water with her parents but two other children, a 10-year-old boy and girl were still missing.
In an update late Wednesday night, the mayor said the body of a 10-year-old boy was recovered around 10 p.m., and the 10-year-old girl was still missing.
The 11-year-old girl who managed to get out of the river on her own is the sister of the 10-year-old boy who was found dead. The other girl who is missing is their friend, the mayor said.
"She expressed that they were in the water they were trying to get out she got out at a different point not too far from here - she is back with her mother and she's worried about her brother as well as the friend that was with them," Lora said.
Lora said a man in the park jumped into the water to try and save them but when he was about five meters deep, it was too deep and the current pushed him away and he could not reach them.
The mayor said divers were going back into the river, fighting the weather and current.
He called the operation a recovery mission as rescuers continue to search for the 10-year-old girl.
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