The first person to land on the moon was Neil Armstrong
The Shays insurgents claimed they were fighting for liberty as they did in the Revolution while the governor and other political leaders saw it as tyranny. The political leaders saw this as a threat to government and to the security of life and liberty. Additionally, there were former veterans fighting on both sides. Thomas Jefferson, while away in France, thought that "a little rebellion now and then is a good thing". He thought it was necessary for the health of the government. (Actual answer)
I wonder whether there would be also other options, but one very important aspect is the smog: the city center is where many industry-relevant things meet: the factories are all around it, transport, cars... and since it is surrounded by bad air, the air takes longer to dissipate. This is especially visible if the city is in a valley, such as Mexico city foe example.