SAN ANTONIO — Firefighters responded to a structure fire in a neighborhood north of downtown in the 900 block of Capitol Avenue early Tuesday Monday morning. 

According to officials with San Antonio Fire Department, around 1:20 am, the fire affected at least two unoccupied residential structures, possibly a third, as well as two garage structures. 

As of this morning, the cause of the fire is unknown. However, arson investigators were called out to the scene. 

Officials tell KENS 5, at least one of the structures will be a total loss.