Although　through　tied-arch　bridges　exhibit　strong　structural　robustness,　collapse　incidents　triggered　by　the　progressive　failure　of　hangers　still　occasionally　occur.　Given　that　such　bridges　are　unlikely　to　collapse　due　to　the　damage　of　a　single　or　multiple　hangers　under　the　serviceability　limit　state,　this　study　focuses　on　the　failure　safety　limit　state.　Using　the　Nanfang＇ao　Bridge　with　inclined　hangers　and　the　Liujiang　Bridge　with　vertical　hangers　as　case　studies,　this　paper　investigates　the　dynamic　response　and　failure　modes　of　the　residual　structures　when　single　or　multiple　hangers　fail　and　initiate　progressive　collapse　of　all　hangers.　The　results　demonstrate　that　the　configuration　of　hangers　significantly　influences　the　distribution　of　structural　importance　coefficients　and　the　load　transmission　paths.　Under　identical　failure　scenarios,　the　Nanfang＇ao　Bridge　with　inclined　hangers　remains　stable　after　the　failure　of　four　hangers　without　experiencing　progressive　collapse,　whereas　the　Liujiang　Bridge　with　vertical　hangers　undergoes　progressive　failure　following　the　loss　of　only　three　hangers,　which　indicates　that　inclined　hanger　configurations　offer　superior　resistance　to　progressive　collapse.　Based　on　the　aforementioned　analysis,　the　LS-DYNA　Simple-Johnson-Cook　damage　model　was　employed　to　simulate　the　collapse　process.　The　extent　of　damage　and　ultimate　failure　modes　of　the　two　bridges　differ　significantly.　In　the　case　of　the　Nanfang＇ao　Bridge,　following　the　progressive　failure　of　the　hangers,　the　bridge　deck　system　lost　lateral　support,　leading　to　excessive　downward　deflection.　The　deck　subsequently　fractured　at　the　mid-span　(1/2　position)　and　collapsed　in　an　inverted　＂V＂　shape.　This　failure　then　propagated　to　the　tie　bar,　inducing　outward　compression　at　the　arch　feet　and　tensile　stress　in　the　arch　ribs.　Stress　concentration　at　the　connection　between　the　arch　columns　and　arch　rings　ultimately　triggered　global　collapse.　For　the　Liujiang　Bridge,　failure　initiated　with　localized　concrete　cracking,　which　propagated　to　reinforcing　bar　yielding,　resulting　in　localized　damage　within　the　bridge　deck　system.　These　observations　indicate　that　progressive　stay　cable　failure　serves　as　the　common　initial　triggering　mechanism　for　both　bridges.　However,　differences　in　the　structural　configuration　of　the　bridge　deck　systems,　the　geometry　of　the　arch　ribs,　and　the　constraint　effects　of　the　tie　bar　result　in　distinct　failure　progression　patterns　and　ultimate　collapse　behaviors　between　the　two　structures.　Thereby,　design　recommendations　are　proposed　for　through　tied-arch　bridges,　from　the　aspects　of　the　hanger,　arch　rib,　bridge　deck　system,　and　tie　bar,　to　enhance　the　resistance　to　progressive　collapse.