▶ Watch Video: The search for missing 9-month-old sibling continues after 2-year-old found in Delaware River

Authorities are still searching for a missing 9-month-old baby who was among those swept away in a spell of deadly flash flooding that ripped through parts of suburban Pennsylvania last weekend. At least six people were confirmed dead in the aftermath of the extreme weather, including a 2-year-old toddler named Mattie, the sister of the baby who has not yet been found.

The ongoing search for the 9-month-old baby, Conrad Sheils, depends on the conditions of the Delaware River, the Upper Makefield Township Police Department said in a Facebook post Sunday morning. Flash flooding that hit the area on July 15 was particularly devastating for a portion of Bucks County about a mile from Houghs Creek, a tributary in the Delaware River that is about 30 minutes north of Philadelphia by car, the police department said in a previous update. 

At the time, authorities reported that flash flooding had submerged part of a roadway in the creek’s vicinity with five feet of water. Of the estimated 11 vehicles on the roadway when flash flooding hit, three were swept away, while eight people were rescued from their cars and three were rescued from the creek. 

Three adults were found dead outside their cars, with seven people in total reported missing after the flooding. Conrad was the only one in that group who had not been located as of Sunday, according to Upper Makefield Township police. The department confirmed that Conrad’s sister was found dead Friday. Authorities located the child’s body near the Philadelphia wastewater disposal plant, which is more than 30 miles away from the site of the flash flood, CBS Philadelphia reported.

“We are devastated that we have not yet been able to reunite Conrad with his sister and family,” the police department wrote in its latest Facebook post.

Efforts to find victims of flash flooding over the last eight days have involved hundreds of people from search and rescue teams, marine crews and police and fire departments. The rescuers used K-9 dogs, drones, sonar technology, boats and air units, police said. 

A debris pile underwater near the juncture where Houghs Creek meets the Delaware River is the only section of the search area that still needs to be probed, according to the department, which noted that divers will explore the wreck when “conditions permit.” Islands in the area that were probed already will be explored again as water levels continue to recede amid the ongoing search for Sheils.

“And to Conrad, we will never stop until we can bring you home,” Upper Makefield police said on Facebook. “We love you and as do so many people who have been following this tragic event. If love was enough to bring you home, we would have found you a long time ago.”