Lorry crashes off Merthyr flyover after car collision
Police are appealing for witnesses to a crash between and a car and a lorry, which then went off the road and dropped on to a grass verge.
Police said the incident involving a green Vauxhall Astra and a heavy goods vehicle happened at about 1300 GMT on the A465 at Merthyr Tydfil.
The lorry driver was taken to Prince Charles Hospital, Merthyr Tydfil, with serious injuries.
The road was closed in both directions while an investigation was carried out.
Two people in the car were also taken to hospital but police said neither had life-threatening injuries.
The incident happened on the A465 Heads of the Valleys road between Dowlais and Cefn Coed.
The fire service said the 38-tonne lorry had fallen around 20ft (6m) near Pant Industrial Estate.
South Wales Police said it was believed the lorry left the carriageway after it was in collision with the Astra.
Witnesses can contact police on 101 (if in Wales) or on 0845 6071002 or call Crimestoppers anonymously on 0800 555 111.