The fire at a three-storey property in Dickens Road, Low Hill, on December 30 resulted in the death of a man. Thirteen other people were evacuated from the building but nobody else was hurt.
West Midlands Fire Service investigators have concluded that the incident was caused by an "electrical issue" at the premises.
The fire broke out at about 1am on the second floor of the bedsit accommodation.
Following the incident West Midlands Police set up a cordon outside the premises and said the fire was not being treated as suspicious.
A total of 13, mainly young adult residents, had managed to get outside as firefighters including crews from crews from Bilston, Dudley and Willenhall arrived at the scene.
Despite the best efforts of paramedics, the man was confirmed by West Midlands Ambulance Service as having died at the scene.
The fire brigade posted on Twitter: "Our fire investigators believe this fire on 30 Dec, in which a man very sadly died, started accidentally because of an electrical issue."