Video posted to social media shows vehicles scattered across the interstate, including 18-wheelers that appeared to have crashed into vehicles or veered into the median.
Authorities think a “quick-arising dust storm” ultimately caused the pileup. “It appears as though there was heavy winds, causing a dust storm with zero visibility,” Nelson said.
A summary of the storm from the National Weather Service showed there were wind gusts up to 64 mph in Hardin around 4 p.m. local time Friday.
The names and ages of the dead had not been released as of early Saturday. Authorities said there also were injuries in the pileup, but exact figures were not given out.
Montana Gov. Greg Gianforte (R) wrote on Twitter that he was “deeply saddened by the news of a mass casualty crash near Hardin.”
“Please join me in prayer to lift up the victims and their loved ones,” he wrote. “We’re grateful to our first responders for their service.”
I’m deeply saddened by the news of a mass casualty crash near Hardin. Please join me in prayer to lift up the victims and their loved ones. We’re grateful to our first responders for their service.
— Governor Greg Gianforte (@GovGianforte) July 16, 2022
Montana Attorney General Austin Knudsen (R), who oversees the Montana Highway Patrol, said in a statement on Facebook that the agency and first responders were investigating the incident.
“We will release more information as it becomes available and is appropriate out of respect of the lives lost and their loved ones,” Knudsen said. “My prayers are with everyone affected by the tragic events during the dust storm in Big Horn County today.”
Thunderstorms on Friday afternoon prompted strong-wind warnings in the Billings area, according to the Weather Service. Severe-thunderstorm watches and warnings were issued by the National Weather Service for south central and southeastern Montana on Friday.
The storms produced surging winds known as outflows that were sent toward Hardin. In addition to the wind gusts, meteorologists had forecast potential isolated quarter-size hail and frequent lightning.
“This outflow cannot be seen on radar, so take appropriate actions now to be weather-ready!” the National Weather Service tweeted.
Strong winds from an outflow could impact portions of SE MT and Sheridan County, WY, for the next couple hours. This outflow cannot be seen on radar, so take appropriate actions now to be weather-ready!#mtwx #wywx pic.twitter.com/KQMr1Q8VWX
— NWS Billings (@NWSBillings) July 15, 2022
The crashes started around 4:50 p.m. local time Friday, according to an incident map for the Montana Department of Transportation. Traffic was shut down for hours on eastbound I-90, and the westbound side of the interstate was reduced to one lane.
Nick Vertz, a Weather Service meteorologist in Billings, told the AP that winds of that nature could easily pick up dust, quickly making visibility difficult.
“If they looked up in the sky while they’re in Hardin, they probably didn’t see much of what you’d think of for a thunderstorm cloud, maybe not even much at all,” Vertz said. “It was just a surge of wind that kind of appeared out of nowhere.”