A 42-year-old man was taken to hospital in critical condition, after being hit by a vehicle downtown.
Ottawa paramedics say he suffered severe head, neck and leg injuries; he remains in the Intensive Care Unit.
The collision happened on Kent Street near Catherine Street around 10:20 p.m. Tuesday.
Police say the driver of the vehicle fled the scene on foot. Police have a male suspect in custody who was arrested near the scene. They won't confirm if the suspect was the driver of the vehicle.
Police have not laid any charges and the collision unit is continuing to investigate.
The intersection of Kent Street and Catherine was closed for several hours overnight, along with the Highway 417 eastbound off-ramp to Kent Street. Police have reopened all the roads.