The cause of the fire remains under investigation.

FORT WORTH, Texas — Several people are displaced after an early morning apartment fire in Fort Worth Thursday, officials say. 

According to the Fort Worth Fire Department, crews received calls about smoke coming townhome apartments in the 2011 block of Remington Street just before 6:30 a.m. 

The first crews on scene declared a working fire and ensured everyone was out of the building safely. 

The fire became aggressive and a second alarm was called. The Incident Commander on scene made the decision to fight the fire defensively and evacuate all fire personnel from the building, officials say. 

The fire was declared under control after an hour, with help from crews from the River Oaks Fire Department. 

Fire officials say the building, including all four units, was heavily damaged. Red Cross was called to the scene to assist the 13 adults that are displaced. 

No injuries were reported, according to the Fort Worth Fire Department. The cause of the fire remains under investigation.Â