Initial reports indicated that police had been responding to a call about a man with a knife on the streetcar near Dundas Street West and Bathurst Street, at the time of the shooting.

The circumstances of the shooting are now being probed by Ontario’s Special Investigations Unit.

The SIU investigates all incidents involving police in which death or serious injury occur, or when allegations of sexual assault are raised.

http://www.cbc.ca/news/canada/toronto/story/2013/07/28/toronto-ttc-streetcar-fatal-police-shooting-siu.html