The A140 remains closed and three people have been taken to hospital after a serious crash between a lorry and a car in Creeting St Mary.
Police officers, fire crews and paramedics all responded to reports that two vehicles collided on the junction between the A140 and All Saints Road, with the initial reports coming in shortly after 11.30am.
The A140 was closed in both directions for most of the day while crews from Suffolk Fire and Rescue Service freed the casualties from their vehicles using cutting gear.
A spokesman for the East Anglian Air Ambulance service said: "A woman in her thirties was treated at the scene before being flown to Addenbrooke's Hospital for further treatment.
"A man in his forties and a young boy were also assessed and treated at the scene before being transferred to Ipswich Hospital by road ambulance, with members of the East Anglian Air Ambulance team in attendance."
The East of England ambulance service said the woman who was flown to London was in a serious condition.
Recovery arrived at the scene at 4.50pm to assist in reopening the road, which is being managed by Highways England.
Two East Anglian Air Ambulance helicopters were tasked to assist the ambulance, police and fire crews with the collision, with the first air ambulance arriving on scene at 11:48am.
Seven fire crews also attended the scene from Princes Street in Ipswich, Debenham, Needham Market and Stowmarket.
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