If nuclear war breaks out? Here Are 7 Devastating EffectsDivya Delhi: A nuclear war between India and Pakistan is a common rumor online amid their growing tensions. Nuclear weapons' widespread devastation and radioactive fallout that harms genetics make them the most dangerous man-made invention. The first and only use of atomic weapons in combat was the US bombings of Hiroshima and Nagasaki on August 6 and 9, 1945, respectively. By 1945, the bombing killed over 140,000 people in Hiroshima and 74,000 in Nagasaki.  A single nuclear weapon can devastate a city and kill most of its population. Multiple nuclear blasts above cities might be disastrous. Tens of millions could die in this scenario.  Reports say a nuclear explosion's fireball reaches its maximum size in 10 seconds, unleashing immense blast, heat, and radiation. After the explosion, the shockwave travels hundreds of kilometers per hour and can do unimaginable damage. The blast can kill people near ground zero and cause lung damage and internal bleeding far away.