PORTLAND — Portland police are investigating a crash on Preble Street in which a witness said that at least one person had to be placed on a stretcher and transported by ambulance from the scene.

Lt. Robert Ridge said the crash, which may have involved a car and pedestrian, took place around 9 p.m. on the section of Preble Street closest to Back Cove Trail and the Hannaford supermarket.

No other details were immediately available.