Calgary police are now investigating after a young woman was dropped off at the South Health Campus in grave condition.
Police cars and an unmarked police car were spotted parked outside the hospital on Thursday evening.
They say the woman was dropped off at the hospital by a cab at around 4 p.m.
According to police, she had ingested some sort of substance and fell critically ill.
The police were notified about the situation later on in the evening.
The woman remains in critical condition.
