A second woman has died after a car hit a group of pedestrians at Withington Hospital, Greater Manchester Police said.
Greater Manchester Police (GMP) said officers were called to reports of a serious collision in a car park at Withington Community Hospital shortly after 2.05pm on Tuesday.
Two women were taken to hospital with life-threatening injuries and both later died.
An 89-year-old man was arrested on suspicion of causing death by dangerous driving and serious injury by dangerous driving and is in police custody.
Senior Investigating Officer Sergeant Lee Westhead, from the Serious Collision Investigation Unit for GMP, said: "My thoughts go out to anyone affected by this tragic incident.
"An investigation has commenced to establish the circumstances.
"We are in the very early stages of the investigation and I would urge anyone who witnessed the collision, or saw the vehicle beforehand, to contact my team as soon as possible."
A spokeswoman for North West Ambulance Service said: "We were called at 2.05pm to attend reports of a road traffic collision involving a vehicle and pedestrian."