At least seven people have been killed and dozens injured as a lorry crashed head-on into a Greyhound bus in the US.
The collision happened on Thursday on a highway near the town of Thoreau, New Mexico.
Officials say the death toll is likely to rise. State police say 49 people were on board the bus at the time.
It came as millions of Americans head into a three-day holiday weekend to celebrate Labor Day.
Rachel Cunningham told CBS News she was asleep on the Greyhound at the moment of impact.
“It was horrifying,” she said, “Like, I’ve never actually seen in my life a bus look like a ripped-open sardine can.”
New Mexico State Police Officer Ray Wilson said that according to witnesses, a tyre on the lorry blew out, causing it to plunge into oncoming traffic.
According to Greyhound, the bus had departed from St Louis bound for Los Angeles.
It stopped in Albuquerque just before the collision, the company said.
“Our first priority is taking care of our passengers and their families as this incident has deeply impacted all involved,” the company said.
“Our thoughts and prayers are with everyone as we continue to give our support to all affected.”
Passing motorists on Interstate 40 described coming upon the harrowing scene, with victims struggling to pull themselves from the mangled bus.
Several described seeing passengers on the ground, screaming and crying.
The front of the bus had been ripped off, and the lorry was overturned with debris scattered across the grassy median.
Rescuers and witnesses used ladders to get passengers out of broken windows. Nearly every person on board was transported to hospital, CBS reported.
Eric Huff was driving to the Grand Canyon with his girlfriend, when he came upon the crash.
He said the truck was “shredded to pieces”.
“It was an awe-inspiring, terrible scene,” he said.
Chris Jones – a Navy veteran and volunteer firefighter – described coming across the wreckage only seconds after the crash occurred.
“It was a lot of screaming and yelling and a lot of people in need,” he told CBS from his home in southern California.
“There was people stuck inside the bus, screams from in there wanting to get out.
“It was non-stop, there wasn’t enough ambulances there to get everybody out. It was just a struggle.”
Greyhound’s intercity buses have provided budget travellers an affordable way to see America for nearly a century.
The American Automobile Association (AAA) estimates that as many as 35 million Americans will travel at least 50 miles (80km) over this holiday weekend, which traditionally marks the end of summer.