The blaze at the three-story structure on Gordon Street caused high-reaching flames and forced one unit to collapse. The adjacent units were damaged.
"It was really crazy. I can't even explain it, really," said witness Alex Kelly. "I was just thinking 'is everyone okay and stuff like that.'"
65 firefighters responded, according to a release from Durham Fire Department. The fire took about 30 minutes to get under control. No one was injured.
Investigators are looking into what caused the fire.