Complex sentence: Striving to keep their control over the town at any cost, the retreating troops of Admiral Kolchak detonated the sixth span of the bridge, one end of which fell into the river and was strongly deformed.
Split into simpler sentences: Striving to keep their control over the town at any cost, the retreating troops of Admiral Kolchak detonated the sixth span of the bridge. One end of the truss fell into the river and was strongly deformed.