FORT WORTH -- One person was killed after a fire broke out at a Fort Worth apartment complex.

Fire officials were called to the Brazos on Hulen Apartments in the 6600 block of South Hulen Street just before 9 p.m. Thursday and found "heavy fire" showing from the apartments, according to the Fort Worth Fire Department.

Firefighters found an elderly male with severe burns and an elderly female who had escaped but was injured. They were both taken to Parkland Memorial Hospital in Dallas.

One of the patients has since died, according to the Dallas County Medical Examiner's Office, but an identity hasn't been released.

The fire was under control by 9:08 p.m. Fire crews determined that two units were damaged heavily, while two had "extensive smoke damage." About 32 units were without power after the fire.

Ten people were displaced and are being helped by the American Red Cross.

The cause of the fire is believed to be from someone smoking in the same room as an oxygen tank.