Around 2-30pm on December 3rd, a blue Honda Jazz car and a white Ford Transit van were involved in a collision on Whalley Road.
The driver of the Honda, a 90-year-old man and a 93-year-old woman, a passenger in the vehicle, suffered serious injuries and were taken to Royal Preston Hospital. The woman died on December 6th. The man is currently recovering.
The driver of the Ford, a 30-year-old man from Accrington, was not injured.
The road was closed for close to three hours while accident investigators attended the scene.
Sgt Andy Ainsworth, of Lancashire Police, said: “These are tragic circumstances and my thoughts are with the woman involved and her family at this very sad time.
"We continue to appeal for information and if you saw what happened and have yet to speak to police, please come forward."
Anyone with information can contact police on 101 or email [email protected] log 0757 of December 3.