HOUSTON (AP) -

One firefighter has been hurt battling a Houston apartment complex blaze but all of the residents safely evacuated.

Arson investigators were dispatched to the scene of the three-alarm fire reported early Monday.

Authorities are trying to determine what sparked the fire in northwest Houston that left a firefighter with minor injuries. The firefighter was transported to a Houston hospital. Further details on him weren't immediately released.

The fire was extinguished before dawn Monday.