TULSA, Oklahoma - Firefighters knocked down a large apartment fire at the Deerfield Estates Apartments in south Tulsa on Saturday. They now believe the fire started in a first floor apartment and spread from there.  

The apartments are located in the 8800 block of South Delaware.

Three firefighters were injured, but TFD Capt. Stan May said they have been treated and released to go home.

Two of the firefighters received burn injuries when a balcony collapsed on them while they were operating near one of the first story apartments where the fire began. They will report to the burn specialist to continue treatment on Sunday, May said.

The third firefighter received injuries to his ribs when ceiling and attic materials collapsed on his crew working on the second floor. He will report to the City Physician on Monday to determine his course of treatment, May said.

"The cause of the fire has been determined to be 'improperly discarded smoking materials.' The fire started in some items stored in boxes outside one of the downstairs apartments, it quickly spread up the outside of the structure," May said.

Just before 11:30 a.m. firefighters were called to the complex. Even before they arrived, flames could be seen coming from one of the buildings.

Officials also report a child at the complex was suffering from smoke inhalation and was treated by EMSA paramedics.

The Red Cross is now helping the families impacted by the fire.