Investigators said the blaze appeared to be accidental, originating from the HVAC utility closet in a second-floor apartment, according to the release. The exact cause of the fire is undetermined.
The residents were in the unit when the fire started and were alerted by the smell of smoke, officials said. They got out on their own and began banging on doors to alert their neighbors.
Two units sustained heavy fire damage, and two others had extensive smoke, heat and water damage.