A driver in his 50s died and 100 people had to be led to safety when a chemical tanker crashed and caught fire on the M6 in Staffordshire on Monday night.
An exclusion zone had to be set up around the scene of the crash
The accident resulted in a mass evacuation of the motorway, with drivers having to leave their cars between junctions 15 and 16.
A lorry broke through the central reservation and hit a tanker carrying carbon dioxide, the fire service said.
An exclusion zone had to be set up because of the danger of an explosion.
Up to 105 people sought refuge at nearby Keele motorway services, which was just outside the cordoned-off area.
Two cars also became caught up in the collision with the lorry and the tanker, police said.
The man who died was from the West Midlands, but it is not yet clear which vehicle he was in.
The tanker was carrying 23 tonnes of carbon dioxide cylinders.
A Staffordshire Ambulance Service spokesman said the tanker exploded after the crash and that a service doctor who arrived at the scene shortly after the collision reported seeing the fire.
He said: "The doctor described the flames as being 50ft into the air and when he arrived, one of the lorry drivers had been dragged out by two motorists who had stopped."
Police led drivers to safety off the motorway
A woman told the BBC that motorists had left their vehicles and walked to the rendezvous.
She said: "Out the car we got and we had to keep on walking back, kept on walking. We were on the central reservation for quite a long time."
The Central Motorway Police Group (CMPG) said another driver was in a critical but stable condition at the University Hospital of North Staffordshire.
A CMPG spokeswoman said officers were investigating the cause of the crash, which happened shortly before 2050 GMT.
The motorway reopened to northbound traffic early on Tuesday and two lanes of the southbound carriageway reopened at about 1230 GMT.