A bus driver has been arrested on suspicion of causing death by dangerous driving after a crash on the M5 in which a man died.
About 40 people were injured when a lorry slammed into the rear of a bus which had broken down in the inside lane of the motorway in thick fog.
Witnesses said visibility was "poor" when the crash happened at dawn on Saturday between junctions three and four, southwest of Birmingham.
The 49-year-old bus driver, from Birmingham, was held and released on bail after a 35-year-old man, also from the city, died.
Two people, including the lorry driver remain in serious condition. Others suffered less serious injuries.
Firefighters said one person had to be cut out of the lorry while two people were cut out of the bus, which did not have seatbelts fitted.
Some were treated on the scene, others were taken to various hospitals in the area, including the Queen Elizabeth Hospital in Birmingham.
The motorway was closed for several hours in both directions between Bromsgrove and Halesowen. It later reopened.
The coach, which was carrying fruit pickers to a site in Evesham, in Worcestershire, was shunted into the central crash barrier by the force of the lorry hitting it.
Passenger Mandip Singh told Sky News: "It was totally scary. I'm in shock."
Investigators are carrying out an inquiry into the cause of the accident and the southbound M5 lane is likely to remain closed until at least the end of today.
The lorry's owner Fowler Welch said in a statement: "At this stage the facts are not fully known.
"Our thoughts and concerns are with those involved and their families. We will be co-operating fully with the police and emergency services to aid them in their investigation."
Nathan Hudson, from West Midlands Ambulance Service , said described the incident as "verging on carnage".
"The conditions at that time weren't great - it was quite foggy," he said.
"Therefore our crews and also the other emergency personnel... had to work under extreme conditions to transport the patients and critically ill to hospital."
He said the wounded suffered a range of injuries, including blunt trauma and limb fractures.
Penelope Morgan, who reported the crash to police, told Sky News: "Approaching the coach, where the fog was so thick, you couldn't see hand in front of you.
"The hazards on the coach were very dim, the lights were very dim as well, and until you got right on top of it, you couldn't actually see it."
Martin Stott, of the Highways Agency , said signs warning of an incident and urging drivers to slow down were put in place after an initial call saying the coach had broken down.
Fog warnings were already in place, Mr Stott said, adding: "We'd set information across the network on our display signs to say that there was fog and to slow down."