A DC-10 aircraft was unloaded following a charter flight. Company maintenance personnel placed damaged passenger seatbacks containing solid-state chemical oxygen generators in the forward cargo hold with seat covers and oil. A mechanic inspected the seatbacks and discovered a loose oxygen generator. Improper handling of the oxygen hose resulted in the generator activating, generating 430øC heat. Seat covers ignited, and the fire rapidly spread through the cabin, ultimately engulfing the floor. The incident was likely caused by an oxygen system malfunction.A DC-10 aircraft was unloaded following a charter flight. Company maintenance personnel placed damaged passenger seatbacks containing solid-state chemical oxygen generators in the forward cargo hold with seat covers and oil. A mechanic inspected the seatbacks and discovered a loose oxygen generator. Improper handling of the oxygen hose resulted in the generator activating, generating 430øC heat. Seat covers ignited, and the fire rapidly spread through the cabin, ultimately engulfing the floor. The incident was likely caused by an oxygen system malfunction.