Mohenjo-Daro which means ‘Mound of the Dead Men’  is an archaeological site in the province of Sindh, Pakistan. Built around 2500 BCE, it was one of the largest settlements of the ancient Indus Valley Civilisation, and one of the world’s earliest major cities. Mohenjo-Daro was abandoned in the 19th century BCE as the Indus Valley Civilization declined, and the site was not rediscovered until the 1920s. 
However, in contrast to the well-appointed houses and clean streets, the uppermost levels at Mohenjo-Daro contained squalid makeshift dwellings, a careless intermingling of residential and industrial activity, and, most significantly, a series of more than 40 sprawled skeletons lying scattered in streets and houses. Numerous other skeletons were found within layers of rubble, ash, and debris, or lying in the streets in contorted positions that suggested the agonies of violent death.
The Ancient City of Mohenjo-Daro Has Survived 5 Millennia but May Disappear in 2 Decades.
And then there is the question of where the rest of the inhabitants are? Archaeologists estimate that at its peak, Mohenjo-Daro was home to some 40,000 people. So why only forty-four bodies? To date, no cemetery has ever been found in Mohenjo-Daro or its surroundings. 

There were many objects found within the ruins that seem to be fused together from the heat that would have to be at least 1500°C to do so, as well as melted bricks only from a single direction. One of the skeletons brought to a lab for research had 50 times the radiation level normally found in a human body. The only known weaponry that causes devastation in the manner found at Mohenjo-Daro is atomic which is a suggested theory.
One other theory suggests that declining monsoons impacted water availability in Ghaggar-Hakra (an intermittent river in India and Pakistan that flows only during the monsoon season) and that in turn caused the societal changes. Around 4000 years back, a dramatic climate change happened across North Africa, the Middle East, the Tibetan Plateau, southern Europe, and North America. In India, during that period, there was an abrupt shift in monsoons, which lasted two centuries. In general, if you observe the patterns of recent years, monsoons have strong years and weak years, but they rarely deviate far away from the mean due to the dynamic feedback systems. It is a self-regulating system, but there have been occasions when the anomaly has lasted for few decades. But what happened 4,000 years back was truly unusual; it was an anomaly larger than anything the subcontinent had faced since in the last 10,000 years.
There are many fascinating tales concerning this fallen ancient city that we shall never know about.

Read the entire blog from the link Vile Vortices Part 2