Complex sentence: The first unit from the 5th Infantry Division arrived at the bridge at 16:15 and mounted a successful attack, the removal of the demolition charges, had prevented the Italians from destroying the bridge.
Split into simpler sentences: The first unit from the 5th Infantry Division arrived at the bridge at 16:15 and mounted a successful attack. The removal of the demolition charges had prevented the Italians from destroying the bridge.