Temple firefighters are working to determine the cause of a fire that prompted the evacuation of an apartment building on South 5th Street early Monday morning.

Crews were dispatched to The District at 21 Fourteen Apartments at 2114 S. 5th at 12:19 AM in response to reports of a mattress on fire outside the building. When firefighters arrived, they learned that the mattress fire had been extinguished.

While checking the safety of individual apartments, they noticed smoke coming from an upstairs unit and began evacuating families. The call was then upgraded to a structure fire.

Thankfully, no injuries were reported, and the scene was cleared by 3:07 AM.

Fire crews determined that the smoke was coming from the attic. Investigators could not say what may have caused the blaze, and were still working the scene late Monday morning.

The four families displaced are receiving assistance from the American Red Cross.