The fire was reported at 6:07 a.m. at a building near the intersection of 20th and A streets, the dispatcher said.
Firefighters responded and had the fire under control as of 7:35 a.m., she said.
The two-story building where the fire was reported has retail space on the ground floor and residential units on the second floor.
No injuries were reported due to the blaze, the dispatcher said.
The cause of the fire is under investigation.