Two people were taken to hospital after a collision between an HGV and a van that closed the A47 for ten hours between Wisbech and Guyhirn.
Police launched a witness appeal to try to determine what happened on the stretch just before midnight last night (September 24).
Officers re-opened the road at 10.10am this morning.
Sgt Declan McDonagh said: “Two men in their 30s have been taken to hospital with serious injuries.
“I would urge anyone who saw this incident or those who may have dashcam footage to get in touch.”
The road remained closed overnight while extensive investigations took place.
Highways officials recommended a diversion of almost 50 miles during the busy morning commuter rush while investigations continued.
But instead bus service FirstNorwich tweeted to inform passengers they would be diverting via Wisbech St Mary – a mere two mile trip instead.
The recommended diversion would take motorists out on the A141 towards Chatteris and then to Ely before picking up the A10 to head north towards King’s Lynn.
Those travelling in the opposite direction were urged to head along the A1101 to Outwell, out to the A10 and onto Ely before heading back through Chatteris and along the A141 to Ring’s End.
Cambs fire and rescue were also at the scene and confirmed that two casualties were taken to hospital.
“Two crews from March were called at 11.55pm and released one casualty, another was already out,” said a fire service spokesman.
“Both were taken to hospital by ambulance.”
Anyone with information is asked to call police on 101 quoting incident 474 of September 24 or report online at cambs.police.uk/report.
Alternatively, you can report anonymously at www.crimestoppers-uk.org/.
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