Pennsylvania authorities drew on 100 people, drones and cadaver dogs in their search for two missing children whose family’s car was swept away in flash flooding that ravaged the East Coast over the weekend.
Other parts of the country endured threateningly high temperatures and severe air pollution from Canadian wildfires.
In eastern Pennsylvania, authorities described Monday’s search for missing Matilda Sheils, two, and her nine-month-old brother Conrad Sheils as a “massive undertaking” along a creek that drains into the Delaware River.
The children are members of a Charleston, South Carolina, family that was visiting relatives and friends when they got caught in a flash flood on Saturday.
The children’s father, Jim Sheils, grabbed their four-year-old son, while the children’s mother, Katie Seley, and a grandmother grabbed the other children, said Upper Makefield Township fire chief Tim Brewer.
Mr Sheils and his son made it to safety, but Ms Seley and the grandmother were swept away.
The grandmother survived, but Ms Seley, 32, was among five killed by the floods.
Pennsylvania’s flash floods also drowned Enzo Depiero, 78, and Linda Depiero, 74, of Newtown; Yuko Love, 64, of Newtown; and Susan Barnhart, 53, of Titusville, New Jersey, Bucks County coroner Meredith Buck said.
The county commissioners signed an emergency declaration in response to the flooding.
Other parts of the saturated Northeast began drying out on Monday after drenching weekend rains resulted in flash flooding in parts of New Hampshire, Massachusetts, Connecticut, New York and New Jersey.
New Jersey governor Phil Murphy declared a state of emergency on Sunday.
The Vermont Emergency Management agency reported that swift-water rescue teams conducted an additional six rescues overnight. The agency also was monitoring areas at risk for landslides.
US transportation secretary Pete Buttigieg and Vermont governor Phil Scott toured some of the destruction from recent torrential rains on Monday, including a damaged inn that was cut in half by flood waters.
Mr Buttigieg said Vermont has endured two storms that would be called “once-in-a-century” events in the span of just 12 years.
More rain was forecast for Tuesday.
Sunday’s storms led to hundreds of flight cancellations at airports in the New York City area and hundreds more flights were delayed.
New York governor Kathy Hochul said five inches (13 centimetres) of rain fell within two hours in Suffolk County on Long Island. The state saw 50 million dollars in damages from storms in the past week.
In North Carolina, floodwaters were blamed for the death of a 49-year-old woman whose car was swept off a road in Alexander County late on Saturday. A man who was in the car with her was rescued.
Meanwhile, extensive swaths of the northern United States awoke to unhealthy air quality on Monday morning or were experiencing it by mid-afternoon, according to the Environmental Protect Agency’s AirNow.gov Smoke and Fire map.
Fine particle pollution caused by smoke from Canada’s wildfires is causing a red zone air quality index, meaning it is unhealthy for everyone.
The particles are tiny enough to get deep into the lungs and cause short-term problems like coughing and itchy eyes, and in the long run, can affect the lungs and heart.
Elsewhere in the US, thousands of people in Kansas and Missouri were without power from weekend storms that swept those states.
Kansas’ largest electric power provider, Evergy, said it could take days to restore service to all customers.
The timeline could create difficult conditions for some people as more storms and stifling heat were expected in Kansas and Missouri early this week, according to the National Weather Service (NWS).
In the West, a mountain biker died on Saturday in blistering desert heat east of San Diego after he and three fellow bikers helped rescue four hikers who were without water.
Cal Fire captain Brent Pascua said the bikers called 911, and two rode back to a trailhead to give directions to rescuers.
A helicopter hoisted the hikers, and the two bikers who had stayed with them headed to the trailhead.
One did not arrive and was found unresponsive about a quarter-mile away. He later died, though there was no information on the cause of death.
Temperatures also soared in Phoenix, which hit 110 degrees Fahrenheit (43.3 degrees Celsius) on Monday shortly after 12.30pm local time, marking 18 consecutive days the city has hit that temperature and tying an earlier record for consecutive days at or above 110 degrees.
Phoenix is expected to surpass the record on Tuesday.
Death Valley, which runs along part of central California’s border with Nevada, reached 128 degrees Fahrenheit (53.3 degrees Celsius) on Sunday at the aptly named Furnace Creek, according to the NWS.
Reno, Nevada, set a record high of 108 degrees Fahrenheit (42.2 degrees Celsius) for the date on Sunday, while also tying the all-time high set on July 10 and 11 of 2002, and equalled on July 5, 2007, according to the NWS.