The Indus Valley Civilization did not vanish suddenly. New research shows many years of droughts slowly weakened this early urban society. Famous cities such as Mohenjo-Daro and Harappa were once built by reliable rivers. But as water became scarce, life turned difficult. People began to leave, settlements shrank, and daily life grew uncertain. The Indus Valley was highly advanced. According to a ScienceDaily report titled 'Scientists finally uncovered why the Indus Valley Civilization collapsed,' the Harappan civilization had organized streets, complex drainage, and water-management systems. They traded as far as Mesopotamia and created a script that remains unread today. Yet, this clever society relied heavily on the Indus River. When the river’s flow changed, everything was affected. Scientists used computer simulations covering thousands of years to study climate. Their models reveal rainfall declined steadily between 5,000 and 3,000 years ago. Some droughts lasted over 85 years. People moved closer to water sources, but eventually, even these dried up. Cities emptied. Around 3,500 years ago, a very long drought matches the major city abandonments. Archaeologists view this period as when the civilization truly started to crumble. Researchers confirmed these models by studying stalagmites and stalactites in local caves. Slow growth in these formations signals less rainfall. Lake sediments also matched the dry conditions. This natural evidence acts like a stone and mud diary of the past climate. Nick Scroxton, a climate scientist, said this research clarifies how changing rainfall shaped ancient city life and farming. Geoscientist Liviu Giosan called the study 'a significant step' in understanding ancient hydroclimate. The scientists are happy their findings match across different evidence, shedding light on how droughts nudged one of history’s greatest civilizations toward collapse.