How flash floods quickly turn into 'wall of water' and how crews face challenges in search

For people caught in the path of a flash flood like the one that claimed at least six lives in Upper Makefield , the key to survival is get as high as possible.

The problem is there is typically no warning beforehand what direction the water is coming from, and it can go from ankle-deep to chest-deep in seconds, according to a water rescue training expert.

It’s the reason that flash floods are the leading cause of weather-related deaths, said Gerry Dworkin, an aquatics safety and water rescue technical consultant with Lifesaving Resources. The Kennebunkport, Maine company trains and supports lifeguard, public safety and rescue personnel internationally.

In a flash flood the water speed doubles, but the water force quadruples, Dworkin said. It's powerful enough to move a vehicle standing in 12 inches of water, where it can be carried into deeper waters.

“You have to get to high ground. What may be a river or stream rapidly overflows and it's a wall of water rushing you,” he said. “There is really nothing you can do. Most people don't carry life jackets in the car.”

Eleven vehicles carrying 19 people in the area of the 1000 block of  Washington Crossing Road around 5:30 p.m. on July 15 were caught in what witnesses and survivors described as a wall of water that crashed downhill from Houghs Creek, a tributary of the Delaware River.

More on Sunday's flash flood vigil 'Angels' oversaw rescues, survivor says at vigil recounting Delaware River fatal flood

Flash floods can quickly become 'wall of water'

Dahlia Galindez, 62, who survived the Upper Makefield flood, described how the water was initially calf-level when she got out of the car as the road started to flood.

She managed only a few steps before she was swept under a guardrail along with her daughter, Katie Seley, 32, and her grandchildren, Matilda "Mattie" Sheils, 2, and 9-month-old Conrad, she told mourners Sunday at a vigil at the Garden of Reflection in Lower Makefield.

Minutes later the water was over their heads. The violent waters stole her granddaughter out of her arms.

Galindez managed to get ahold of a tree limb as chunks of asphalt, drainage pipe and trees swirled in the muddy churning waters, she said. When the water receded, she made her way to a home on Stonebridge Crossing Road where she sought shelter.

Her daughter drowned, along with five others: Enzo and Linda DePiero ages 78, and 74, respectively, Yuko Love, 64, of Newtown Township, Susan Barnhart, 53, of Titusville, New Jersey and her 2-year-old granddaughter, Mattie.

On Friday, Mattie Sheils was found floating in the Delaware River, 32 miles away from the flood scene near Port Richmond. An autopsy ruled her death as accidental drowning according to the Philadelphia Medical Examiner, which performed the autopsy.

On Monday, the search efforts entered the ninth day for Mattie's 9-month-old brother, Conrad.

Her daughter's fiance, Jim Sheils, and grandson Jack, 4, who were also swept over the guardrail survived, Galindez said. They were rescued by firefighters.

Those who perished on July 15 abandoned their vehicles in an attempt to escape the rising waters, according to Upper Makefield police said. But the decision to stay in a vehicle or leave it each carry major risks, Dworkin said.

A vehicle offers the most physical protection from debris and other cars, which can result in physical injuries, Dworkin said.

An autopsy found Yuko Love suffered multiple injuries that contributed to her death, according to the Bucks County Coroner’s Office. Her husband, David Love, who survived by holding onto a tree limb, broke his arm.

Who were Enzo and Linda DePiero They spent more than 40 years together. The fatal flooding took their lives

Difficult decisions: Remain in car or get out in flash floods?

But staying in the vehicle means a risk it will be pulled into deeper waters, where it can sink in 30 seconds to a few minutes, Dworkin said.

In a sinking car, the driver and passengers need to disengage seat belts and lower the passenger windows before the car battery shorts, he said. Window punch tools are useless in vehicles manufactured after 2015 because most side windows are now made of laminated glass, not tempered glass, Dworkin said.

The safest place in a flash flood is the vehicle roof, which keeps the person protected from water, but makes them more visible to rescuers.

“That may be your only high ground,” Dworkin added.

Flash floods also present a danger to people who think they are safe watching nature unfold along the riverbank.  But the volume and speed of the water can erode the surrounding ground as far as 15 feet from the river edge, Dworkin said.

Mattie Sheils found. Where is Conrad? Philadelphia Medical Examiner confirms Bucks County fatal flood victim, Mattie Sheils, 2, pulled from Delaware River

Challenges for rescue and search crews in Delaware River flooding

Flash floods also present unique challenges for rescue and search crews like those still looking for Conrad Sheils.

In non-moving water that is 10-feet deep, the general rule is that the person will be found within 20 feet of where they went under, Dworkin said.  But with flash floods, searchers have to expand their area as much as 10 times the width of the stream or creek because of the volume of water.

Search and rescue crews typically use a Last Seen Point and work from there, but in swift waters there is no good indication where someone swept away might end up.

The decision to expand the ground search along the Delaware River banks and the use of drones to search for the Sheils children was a smart one, Dworkin said.

The use of drones is popular with emergency services agencies because sky searches provide an advantageous position to spot something in water that might not be visible from the riverbanks, Dworkin said.

“What is critical is that the searchers don’t just follow the path of the stream/river; but, rather expand it laterally as the stream/river certainly overflowed its banks and the flow was a lot wider than what they observe now," he added.

Remembering those lost in the flood Remembering the faces of those who lost their lives to the Upper Makefield fatal floods

This article originally appeared on Bucks County Courier Times: Bucks County flash flood took victims in 'wall of water' at Hough Creek