A large fire broke out early Monday morning at a vacant apartment building in northwest Atlanta, according to officials.

Atlanta Fire and Rescue initially received a call about a brush fire, but once crews arrived at the scene they realized that the fire was on the second floor of an apartment on Neal Place in the Bankhead neighborhood, according to spokesperson Anaré Holmes.

Crews had to attack the flames offensively from the outside of the building, Holmes said. “Because of the building integrity issues” firefighters were unable to immediately enter the structure, he explained.

No injuries were reported.

The cause of the fire is unknown at this time, pending an investigation, officials said.