Firefighters were called to near Western Gateway Park at 1305 Locust Street just after 1 a.m. Wednesday.
Crews saw flames in one apartment. They were able to quickly put out the fire.
Firefighters say it appears unattended candles caught a curtain on fire.
No one was hurt in the fire, but one bystander was hurt trying to get people out of the apartment. Paramedics took him to the hospital with a leg injury.
The fire was contained to one apartment and caused under $10,000 worth of damage.