Police were called by the ambulance service shortly after 3pm on Tuesday to reports of a serious collision on Morecambe Road, where a woman walking across a pedestrian crossing close to Ryelands Park was struck by a van travelling towards Morecambe.
A blue Transit Van was later found abandoned in Fairhope Avenue, Morecambe, and two men were seen to run down an alley towards Hamilton Road.
As they did, they passed a woman walking a small dog and police are trying to trace her.
They are also keen to speak to anyone who saw either the collision itself or the van before or afterwards, especially in the Kayswell Road or Fairhope Avenue areas of Morecambe
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Det Insp Andy Ellis of Lancaster Police said: “The young woman involved in this collision spent her 21st birthday in hospital fighting for her life when she should have been celebrating.
“The driver of the van must know the serious nature of the collision and I would urge him to search his conscience and come forward and hand himself in.
“I would also urge anyone who saw the collision or the van before or after the collision to get in touch as they could hold vital information which could assist our enquiry.”
A 29-year-old man from Preston has been arrested and is helping police with their enquiries.
Anyone with information can call 101 quoting log 0873 or the independent charity Crimestoppers anonymously on 0800 555 111.