A 58-year-old woman is dead and a 19-year-old man has what are being described as “life-altering injuries” after they were both hit by a vehicle that mounted a sidewalk and slammed into a building in Burlington on Saturday morning.

Police say that they received multiple calls about a vehicle driving erratically on Fairview Street at around 10 a.m. but by the time they arrived on scene that vehicle had already collided with the pedestrians.

Initial reports suggest that the vehicle left the roadway and struck the male pedestrian on the sidewalk before hitting the female pedestrian as she stood in from of a building that is the former home of a restaurant called ‘Chaps.’

The vehicle then came to a stop after colliding with the outdoor patio structure of that building, police say.

The female pedestrian was pronounced dead on scene while the male pedestrian was airlifted to the Hamilton General Hospital. Police say that one of the male pedestrian’s legs was amputated below the knee as a result of the collision.

The driver of the vehicle, a 73-year-old man, was taken to hospital with a head injury.

Police say that investigators believe the man may have suffered some sort of medical episode that led to the collision, though the investigation is continuing.

“We are looking at a number of different possibilities that could exist as to the source of the erratic driving,” Insp. Derek Davis told CP24 at the scene. “Medical is a possibility, impairment is a possibility and some sort of crime in progress is a possibility. We really won’t know until we have had an opportunity to speak with all of our witnesses and the driver and see what the facts lead us towards.”

Davis said that the vehicle was “well west” of the collision site when it was first seen driving erratically.

He said that the vehicle was spotted veering in and out of its lane and may have also crossed a median at some point.

Fairview Street is currently closed between Woodview Road and Commerce Court as police investigate.