Police remain on scene in the city's north downtown core as a death investigation continues.
Thunder Bay Police Service officers with the Primary Response Branch were dispatched to an address on Cumberland Street South just before 8:15 a.m. on Saturday, February 24 after receiving reports of an injured person.
An adult male was located and received treatment from responding emergency services.
The male was transported to the Thunder Bay Regional Health Sciences Centre and has since died from their injuries.
Members of the Thunder Bay Police Service's Major Crimes Unit and Forensic Identification Unit are involved in the ongoing investigation.
A police presence remains in the area. It is not believed there is a threat to public safety at this time.
Anyone with information is asked to call police at (807) 684-1200. Tips can be submitted anonymously through Crime Stoppers at 1-800-222-8477, online at www.p3tips.com.