WASHINGTON CROSSING, Pa. — Search teams in Pennsylvania were targeting an underwater area Sunday as they tried to find a 9-month-old boy swept away in a flash flood, hours after authorities confirmed his 2-year-old sister’s body was recovered from the Delaware River.

Upper Makefield Township police said in a Facebook post Sunday that although 2-year-old Matilda Sheils had been «taken home to her loving family» after her body was recovered Friday, officials are «devastated that we have yet to be able to reunite Conrad with her sister and family.»

Hundreds of people, including search and rescue teams, marine units, and police and fire personnel, have searched the area with the help of «K-9, sonar, drones, boats, divers, heavy equipment, GPS mapping and airborne units,» police said, adding that they were now at the point where «our search will depend on river conditions.»

Authorities have focused their efforts on an area near where the creek that flooded enters the Delaware River, and plan to use divers there when possible and also station K-9 units on islands in the river as water levels recede. Southern agencies will also check their sections along the river, police said.

“We have no words to describe how we feel, except truly heartbroken. But the pain we feel is nowhere near what these families have been through,» the police statement said, promising the missing boy that «we will never stop until we can get him home.»

Matilda Sheils and Conrad Sheils.Upper Makefield Township Police via Facebook

The girl’s body was found early Friday in the river near a Philadelphia sewage treatment plant, about 30 miles (50 kilometers) from where she was found. taken awayauthorities said late Friday. The Philadelphia Medical Examiner completed an investigation on Saturday and «ruled the cause of death for Matilda Sheils to be drowning and the manner of death is accidental,» an office spokesman said.

The Charleston, South Carolina, family was visiting relatives and friends in the area and headed to a barbecue on the evening of July 15 when their vehicle was struck by a “wall of water” from Houghs Creek, according to Upper Makefield Fire Chief Tim Brewer.

The boys’ father, Jim Sheils, grabbed the couple’s 4-year-old son, while his mother, 32-year-old Katie Seley, and a grandmother grabbed the other children, Brewer said. Sheils and the older boy made it to safety, but Seley and the grandmother were swept away along with the younger children. The grandmother survived but her mother passed away.

Four other people drowned in the suburb about 35 miles (60 kilometers) north of Philadelphia, according to the Bucks County Coroner’s Office: Enzo Depiero, 78, and Linda Depiero, 74, of Newtown; Yuko Love, 64, of Newtown; and Susan Barnhart, 53, of Titusville, New Jersey.