Pine Knoll Shores emergency responders said they were dispatched to the Memorial Park beach access for a water rescue around 3 p.m.
By the time first responders got there, they said two good Samaritans with flotation devices had already reached the three children in the water.
Town officials said a Pine Knoll Shores police officer helped one of the children and one of the good Samaritans to the shore. EMS on a jet ski brought in the two other children and the other good Samaritan.
It took several minutes for lifeguards to find the man, who has only been identified as a relative of the children.
Paramedics performed CPR on him, but he did not survive.
The children were taken to Carteret Healthcare and are in good condition.
The Town of Pine Knoll Shores had red flags posted all day Sunday indicating a high rip current risk.
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