Some scientists believe that the deaths of the city's inhabitants may have been caused by the diversion of the ancient Indian riverbed, the flooding of the river, earthquakes and the resulting floods, or an acute infectious disease. Some have put forward the idea of a massive attack by foreigners who massacred the city's inhabitants in large numbers.
The "Dead Mound" is the historic site of "Mohenjo-Daro" in India. It means "valley of death" in Hindi. Here, the researchers found this place has occurred many times the evidence of violent explosions. The center of the explosion within a radius of 1 kilometer all the buildings were reduced to powder. Farther from the center, many human skeletons were found. The position of the skeletons showed that the catastrophe of death came suddenly and unnoticed by the people. These skeletons strangely contained radiation levels comparable to those of the victims of the Hiroshima and Nagasaki nuclear attacks. In addition, researchers were surprised to find that the rubble field after the burning of the ancient city looked very much like Hiroshima and Nagasaki after the atomic bombings, with traces of shockwaves and nuclear radiation remaining on the ground. The reasons for this are still being debated.
There were also traces of explosions in Mohenjo-Daro City, where they found a center of explosions that flattened buildings in the central area. From this center outward, the farther away it was, the less destruction there was, and at the very edge of the area the buildings were almost intact. This is very similar to the scene after an atomic bomb.
Also, there is a description of the war in an ancient Indian Sanskrit narrative poem, the Mahabharata: "It was as if the might of nature had burst forth at once. The sun was revolving. The hot flames of weapons made the earth burn. Elephants ran wildly from the fire, trying to escape this terrible disaster. The rivers boiled, the beasts died, and the enemy fell piece by piece in a mass of corpses. Horses and chariots were burned, and the whole battlefield was a scene of the aftermath of the great fire. The sea was dead silent, the wind picked up, and the earth lit up. It was a ghastly picture, the bodies of the dead so dismembered and unformed by the terrible fire. We had never seen or heard of such a weapon." This gruesome scene led many to associate this weapon with nuclear bombs. Some even believe that Mohenjo-Daro was destroyed by aliens.
But the theory that scientists currently agree with the most is the lightning destruction theory. Many scientists believe that it was mysterious black lightning that destroyed Mohenjo-Daro. Black lightning evolves from rare ball lightning bolts. Normally, they are small and extremely bright, like a black mist, but contain a huge amount of energy, and are not afraid of normal lightning facilities. When they gather, they can emit poisonous gas and are particularly prone to explosions. As long as there is a black lightning explosion, can cause a chain of explosions, in an instant to produce 15,000 degrees Celsius. The destruction caused by such explosions is similar to the damage done to the city of Mohenjo-Daro, and excavated artifacts from Mohenjo-Daro show that they were subjected to temperatures of 14,000-15,000 degrees. So, the truth could be this: the atmosphere formed black lightning and also produced large amounts of toxic substances poisoning the air. The inhabitants of the ancient city were first tormented by this toxic air for a while, and then the black lightning exploded violently, generating high enough temperatures to melt stone. The shockwave from the explosion destroyed the city when it reached the ground.