The Pittsburgh Bureau of Fire responded to a 3-alarm fire at a warehouse structure in the 1600 block of Smallman Street just after 4:30 a.m.
The building is unoccupied and is currently under construction.
Response to the fire required resources from multiple Pittsburgh Fire companies around the city, as well as Police and EMS.
Firefighters contained the flames before 7 a.m.
There are no known injuries at this time.
The Fire Investigation Unit, which is made up of investigators from Pittsburgh Fire and detectives from Pittsburgh Police, is investigating the cause of the fire.
UPDATE 2:02 p.m. 09/30/2019 - Fire investigators have determined that the cause of this fire is suspicious in nature. The investigation is ongoing.