NETCONG - Authorities in Morris County are working to determine what sparked an overnight fire that killed a Netcong man.

A Netcong police officer on routine patrol called in the fire at 10 Main St. just before midnight, according to the Middlesex County Prosecutor's Office. The three-story building was only occupied by the victim, who lived on the second floor.

Firefighters from several departments were called in to help extinguish the blaze, which was brought under control just after 3 a.m.

Authorities have not released the name of the victim.