About 40 vehicles in M40 fatal crash in Oxfordshire
One man has died in a crash involving about 40 vehicles on the M40 in Oxfordshire.
The motorway was closed northbound for more than eight hours between junction 9 at Bicester and junction 10 at Cherwell Valley services, following the crash at about 07:45 GMT.
Thames Valley Police said one man died at the scene and another person was "critically ill".
Six people were seriously injured and more than 50 have minor injuries.
Police said the person who was critically injured had been taken to hospital, along with those who had been seriously injured and six people with minor injuries.
A further 49 people were assessed at the scene.
The family of the man who died have been informed, police said.
Ch Insp Henry Parsons, of Thames Valley Police, said: "The cause of this collision is under investigation, however, we believe that fog played a major part.
"This has been an extraordinarily large collision, we have not had a collision on this scale for many years in Thames Valley and one man has sadly lost his life."
He added it was a "serious blessing" more people were not killed in the pile up.
The road was closured during investigations and reopened at about 16:30.
Four miles of queues had been reported northbound, with delays of about an hour, according to BBC Travel.
A couple of southbound lanes were also shut along the same stretch.
The Highways Agency also warned of "significant delays" on the diversion routes.
On Twitter, Zara Smith, 31, who was stuck at junction 9, said a number of lorries had jackknifed in "thick fog".
"It was very dense, you could probably see about two cars in front of you when we stopped and that was it," she said.
BBC Berkshire reporter Tim Dellor, who was on his way to Derby for the football match against Reading, said he was held up in the diversion along the B430.
"Part of the problem is all the diverted traffic is congested down these narrow B roads," he said.
Drivers also faced more delays as two Boeing 747 fuselages were transported along the M4 and M5 from Cotswold Airport in Gloucestershire to a scrapyard in Herefordshire.
From the scene
Helen Catt, BBC South Today
More than a dozen vehicles are still standing where they crashed - front wings missing or bumpers crumpled, pressed together at odd angles.
Towards the back of the crush, which reaches right back to the slip road onto the motorway at junction 9, there's a white lorry with a large gash in its side.
The brown boxes it was delivering are clearly visible inside. Next to it sits a private ambulance. In front, a black mini with most of its front gone.
Police investigators have marked the position of each car on the tarmac in yellow spray paint.
Where many other cars have already been moved, there's a thick layer of debris scattered right across all three lanes.