It happened around 4:30 p.m. in the 1100 block of Maplecroft Court in the Brier Creek community.
Four units in the two-story building were damaged. Several people were displaced. One unit was not occupied.
No injuries were reported. One cat was rescued.
Three Durham Fire units responded to assist Raleigh firefighters.
It took about an hour to get the fire under control.
The cause of the fire has not yet been determined.
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