Regulations were dropped about shipping railcars full of vinylcloride.
Remember: keep the government out of our businesses.
This is the issue with capitalism. Proponents say that the free market will alway err on the side of good. The theory being that if a company like this fucks up, customers will go to other providers/suppliers/businesses. But, that doesn't enter into management's mindset. They only care about the immediate share price and the short term viability of the organization. They would rather spend billion of profit on stock buybacks or dividends (which helps all the C-Suite level guys because they likely own a lot of shares or have options to them) instead of upgrading systems.
And Biden has a major role into this as well. He blocked a potential strike from rail workers who wanted sick pay/time. The union has been trying to let people know about this type of deregulation that allows dangerous chemicals to be shipped like this without the proper oversight.
For anyone who knows about the rail industry, the former CEO of both CP & CNR, Hunter Harrison, promoted something called Precision Scheduled Railroading, which boosted profits sky-high, but crushed workers rights. Basically, its a system that allowed the companies to cut the workforce and force customers to ship on the railroad's schedule. It also makes railways less safe for a variety of reasons...
But this sounds like an ecological disaster that isn't going to get better anytime soon.