The fire was reported inside the 12 story apartment building at 2040 Market Street around 8:20 p.m.
The entire building was evacuated.
The small fire was quickly extinguished and residents were allowed back in after the alarm system was reset.
Battalion Chief Kevin Ewing said the fire was likely caused by "some kind of incense."
Ewing said it took a while to find the fire because it was so small.
He said the evcuations were made as a precaution in case there was a larger fire.
No injuries were reported.