A baby has died following a crash on the A12 at Martlesham in Suffolk on Thursday (11 February).
Emergency services were called around 1.45pm to the southbound dual-carriageway, between the Tesco and BT roundabouts.
Police investigating the collision are appealing for the driver of a slate grey 4x4 vehicle to come forward.
The driver thought to be a woman, described as white, in her 40s to early 50s with blonde hair – is being sought as a potential witness as this vehicle is thought to have been behind the two cars involved in the crash.
The 20-month-old girl died in Addenbrooke's Hospital on Friday.
A12 Southbound blocked, queueing traffic due to accident, four cars involved between Eagle Way (Tesco roundabout) and Newbourne Road / Foxhall Road (B.T. Roundabout).