A fundraising campaign is collecting donations to support the family of the man who died this week after rescuing two children struggling to stay afloat in a South Jersey river. Pablo Hernandez Cruz, 49, of Mays Landing, died after he was taken to a hospital, county officials said. He dove into the Great Egg Harbor River, which runs through the Weymouth Furnace Park in Hamilton Township in Atlantic County to help the two children, ages 8 and 12, who struggled in the water Wednesday, officials said. He briefly disappeared while under water, officials said. Swimming is prohibited in the park. Th…