That disaster causes $10,000,000 of harm, but only causes you $90 of harm individually.
You've gained $10, but your $10 gain is a millionth of the harm caused.
Generally-speaking, there's an enormous asymmetry between the cost to create/build and the cost to destroy. So now we have a mechanism by which individuals have a financial incentive to cause harm...
Don't these markets create a mechanism for society to race to self-destruction?