A 22-year-old Toronto man faces an Aggravated Assault charge.
Raejon Raheem Johnson made an appearance in bail court Friday after the original call came in on Tuesday night from the May Street North residence.
Another man was transported to the Thunder Bay Regional Health Sciences Centre (TBRHSC) by Superior North EMS for treatment.
The exact extent of the injuries remains unknown but are considered serious.
If you have information on this event you are asked to call police (807) 685-1200.
You can also submit tips through Crime Stoppers here or by calling 1 (800) 222-8477.