Complex sentence: Pulau Senang is best known in the history of Singapore as a penal settlement experiment that failed after only three years, when a riot against the guards broke out in 1963, killing three officers.
Split into simpler sentences: Pulau Senang is best known in the history of Singapore as a penal settlement in the early 1960s. However, the experiment failed after only three years when a riot against the guards broke out in 1963, resulting in the death of three officers.