Complex sentence: The remains of Serbs massacred by Bulgarian soldiers in the town of Surdulica during First World War I. An estimated 2,000 to 3,000 Serbian men were killed in the town during the first months of the Bulgarian occupation of southern Serbia.
Split into simpler sentences: The remains of Serbs massacred by Bulgarian soldiers in the town of Surdulica during the First World War. It is estimated that 2,000 to 3,000 Serbian men were killed in the town during the first months of the Bulgarian occupation of southern Serbia.