The scene of a crash in which a lorry plunged from a bridge and burst into flames will remain partially closed on Thursday.
The vehicle veered off Colemans Bridge on to the southbound carriageway of the A12 in Witham, Essex, on Wednesday afternoon.
Motorists were urged to avoid the area after the bridge and the road below were closed after the accident, which happened at around 3.45pm.
Essex Police has advised commuters that would usually travel on the southbound side between Marks Tey and Boreham to re-plan their rush-hour journeys, warning that it may remain closed until lunchtime.
Five crews from Essex Fire and Rescue, police officers and an air ambulance attended the scene, and the East of England Ambulance Service said a man was being treated for injuries.
Emergency services crews were still on the scene more than five hours after the accident, the Fire Service said.
Joe McCallum, from Essex, arrived in his van on the other side of the carriageway immediately after the crash and said part of the lorry container was on fire.
A photo he posted on Twitter showed a crumpled vehicle on the barriers of the carriageway below, spilling over into the road.
The 28-year-old van driver said he believed it was a lorry carrying frozen goods, but he could not see anything more due to its “mangled” state.
He said he could not see anybody in the cab following the accident, which forced the closure of the A12 both ways between junction 19 at Boreham and junction 25 by Marks Tey.
The northbound side was later reopened.
Chloe Willis, 20, was in a car travelling to a hockey match with friends and “about five seconds away” from the accident.
The psychology student told the Press Association “black smoke covered the sky” as the lorry caught fire.
She said: “We had to come to an emergency stop as soon as we saw this lorry turned on its side.”
“A big puff of black smoke covered the sky and all the people in cars started to panic.
“You could see where the barriers on the bridge had broken when the lorry had come through.”
Willis said the emergency service response was “pretty instant” with numerous fire engines and police vehicles arriving swiftly.
Essex Police appealed for drivers who may have witnessed the accident or have dash cam footage to contact the force on 101.