A man who fell from a motorway bridge has been taken to hospital by air ambulance.
Police said they received reports of a man lying on the M61 near Chorley at around 9.50am.
The man, believed to be in his 50s, is thought to have fallen from the bridge above in Babylon Lane, Heath Charnock. He was not hit by any vehicles.
He was taken to Royal Preston Hospital by air ambulance where he is said to be in a critical condition.
Both carriageways were completely closed whilst the helicopter landed and took off.
Sergeant Malcolm Bell said: “An investigation is now underway. If anybody saw this man on the bridge prior to him falling then I would urge them to contact police.
“I would also like to speak with anybody who may have seen this man fall.”
Anybody with any information can contact police on 101 or Crimestoppers, anonymously, on 0800 555 111, or online at www.crimestoppers-uk.org.
No personal details are taken, information is not traced or recorded and you will not have to go to court.
Two lanes of the northbound carriageway remain closed due to the incident.
The Highways Agency said the closure was affecting lanes one and two between Junction 6 at Middlebrook and Junction 8 at Chorley.
A spokesman said there were currently delays of 20 minutes caused by congestion.
Normal traffic conditions are expected from midday.