In　2003,　an　8-storey　reinforced　concrete　(RC)　frame-supported　masonry　structure,　located　in　Hengyang　City,　China,　underwent　a　severe　fire-induced　collapse　accident.　Information　on　the　structure　and　the　fire　scenario　is　presented.　It　includes　the　design　data,　the　site　observation　record　of　the　fire　incident,　and　the　laboratory　material　test　results.　Preliminary　investigation　reveals　that　about　45.9%　of　the　bottom　storey　of　the　RC　frame　experienced　temperatures　in　excess　of　800A　degrees　C,　and　its　central　area　reached　1300A　degrees　C.　Such　a　severe　fire　load,　of　fairly　high　temperature　and　large　area,　is　thought　to　be　the　primary　cause　of　the　progressive　collapse　of　the　entire　building　structure.　To　better　understand　the　collapse　mechanism,　this　study　presents　a　coupled　thermo-mechanical　numerical　simulation　of　the　building　collapse.　The　actual　collapse　area　is　well　reproduced　by　the　proposed　numerical　model.　The　simulation　further　demonstrates　that　the　initial　damage　happened　to　two　interior　columns　exposed　to　temperature　of　1300A　degrees　C.　Such　damage　was　also　attributable　to　the　large　gravity　load　they　carried,　and　the　complicated　nature　of　the　local　structural　arrangements.　The　adjacent　structural　members　were　subsequently　damaged,　because　they　were　also　weakened　by　the　fire,　and　were　over-loaded　by　the　redistributed　load.　Failure　of　the　two　interior　columns　and　adjacent　area　eventually　triggered　a　progressive　collapse.　Further,　the　effect　of　some　critical　factors　on　the　collapse　mechanism　is　discussed.　On　the　basis　of　this　numerical　case　study,　practical　design　considerations　on　the　key　structural　components,　the　fire　compartments,　and　the　structural　robustness　are　given　for　the　prevention　of　the　fire-induced　progressive　collapse　of　RC　frame　structures.