The body of a 2-year-old girl who vanished last weekend with her younger brother after a wall of water from intense flooding swept them away was found Friday evening in the Delaware River, officials said.

Authorities recovered Matilda "Mattie" Sheils' body more than 30 miles from where she vanished during flash flooding in Bucks County, Pennsylvania. Her body was discovered after the Philadelphia Police Department received two 911 calls about a body being spotted in the river, Upper Makefield Fire Company Chief Tim Brewer said during a news conference Friday.

"Although Mattie was found 32 miles away from where she was lost, she has never been closer to all of our hearts as she is now," Brewer said.

The child's brother, 9-month-old Conrad Sheils, remains missing after the violent storm battered parts of southeast Pennsylvania last weekend. The children's mother, 32-year-old Katie Seley, was killed in the flash flooding, and her body was recovered last Saturday.

Crews plan to continue searching for Conrad Sheils.

"We will reunite him with his family and sister," Brewer said. "We will work tirelessly to ensure that Conrad is found."

Search efforts are planned to include marine assets up and down the Delaware River as well as K-9 teams and divers, river conditions permitting, Brewer explained.

The Sheils children and their family were visiting from South Carolina and driving to a barbecue when the flash flooding slammed into them, Brewer said Sunday.

The mother and a grandmother grabbed Mattie and Conrad while the father grabbed the children's 4-year-old brother.

The father and his 4-year-old son "miraculously" made it to safety, the fire chief said. But the mother, grandmother and younger children were swept away in the deadly waters.

The children's grandmother survived and has been treated at a hospital, police said.

In addition to the children's mother and Mattie, the storm last weekend killed four other people in Pennsylvania's Bucks County.

The Bucks County coroner identified the other victims as Enzo Depiero, 78, and Linda Depiero, 74, of Newtown Township; Susan Barnhart, 53, of Titusville, New Jersey; and Yuko Love, 64, of Newtown Township. According to a news release from the coroner, they all died from drowning. Love's cause of death was listed as drowning with multiple injuries.

The victims were "caught" in the flash flood, Brewer said at a news conference earlier this week, underscoring they didn't travel into high waters.

"This was a flash flood. ... The wall of water came to them," he said.

Flash flooding happens quickly, generally shortly after intense rain falls faster than the soil can absorb, making it even more life-threatening, according to the National Weather Service. It takes 2 feet of rushing water to carry away most vehicles, including trucks and SUVs, according to the weather service.