The tower was very much so a weather control device. It took millions of gallons of water and turned it into vapor then projected it into the sky. This created a massive sheet of clouds that blended with the constant smog being produced by factories. The tower was powerful enough to blot out the skies of almost all of the Americas.

The machines, who survived on a constant supply of solar power, could not get to us. Yet. Since it was discovered that the Americas were a safe haven, immigration policies were ignored. Billions of people poured into the United States and South America.

Food distribution became a huge problem, hardly anyone had a place to live. Laws were broken, and society was plunged into anarchy.

All while this was happening, the machines had already decimated the rest of the world. It is said that the machines have moved up to the clouds since then, and it is also said that they will come for us.

Hell, they already have.