FORT WORTH (CBSDFW.COM) – When firefighters in Fort Worth were called out to an apartment complex they arrived to find several units engulfed in flames.

It was just after 1:00 a.m. when Fort Worth Fire Department crews arrived at the complex in 1400 block of Vanderbilt Street West, near Eastchase Boulevard and Interstate 30.

Flames spanned from the first-floor level of the building to out of the roof as firefighters worked from the ground to get the 2-alarm fire under control — structural damage caused by the blaze prevented them from entering the building.

It took less than an hour for the nearly 50 firefighters to get the flames under control.

The apartment unit received major damage and several families are being relocated.

No residents or firefighters were injured. Investigators are working to find out what sparked the fire.