Divers recovered the boy's body shortly after 10 p.m. Wednesday, while crews resumed their search Thursday morning for a third child, a 10-year-old girl who remains missing.
Passaic Mayor Hector Lora said the surviving girl told him her brother helped save her life as the children struggled in the water.
According to the mayor, the boy pushed his sister toward rocks near the riverbank, allowing her to climb out safely. The missing girl is their friend, the mayor said.
Lora said rising water levels have made the search for the missing girl more difficult. Initial searches overnight were unsuccessful.
Loved ones stood watch along the Passaic River on Thursday as law enforcement continued their search and recovery operation for the 10-year-old girl from Garfied.
"I actually just saw her two weeks ago at a family gathering, and she's a beautiful little girl, she's very energetic and she's just very creative," the missing girl's aunt said.
Officials believe the three children were playing near a riverbank boat ramp when they entered the water. Children on the opposite side of the river saw what happened and immediately called 911, authorities said.
"The ramp, when it's covered by water, it gives the perception that it's much longer than what it is," the mayor said. "The children appear to have all been on the ramp together and may have dropped in together."
Apparently, witnesses told them to stay away and one man tried desperately to rescue the kids. He ended up in chest-deep water and had to get out.
"He was trying to call them. Like 'get out, don't play in the water,'" said Romeo Vargas, a witness.
Vargas said it was his friend that entered the river after seeing the children in distress, but the current was too powerful. Following heavy rain, some areas of the river may have been deeper than 15 feet, according to the report.
"He was feeling bad because he was trying to save the kids, but he couldn't do it because he didn't know how to swim too much," Vargas said. "He told me that I do it like a father because I have a daughter too. His daughter is probably 6 years."
Relatives are trying to stay strong as authorities from multiple jurisdictions continue their search.
"You still hold onto hope because they haven't found her yet, we're praying that they find her safe and sound," said relative Darrell Miggins.
Lora said the family of the boy who drowned is enduring immense grief. He noted that the children's mother and siblings are also coping with the recent loss of the children's father.
Lora urged the community to focus on supporting the family rather than assigning blame.
"We take 'em to the park - they run around. They play - sometimes you're talking to others. Kids run around. This could happen to anyone, this tragedy. We hope it happens to no one, but right now what this family needs is love and support," Lora said.
The mayor said community members have offered to assist with boats, but he urged residents to stay out of the water and allow trained divers and emergency crews to do the job.
Lora said boat searches were temporarily suspended Thursday night due to low tide and were expected to resume Friday morning, with crews focusing on the river in Rutherford based on the way the current moves. Land searches continued around the clock.
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