They were also able to pay peanuts to send humans into harrowing situations to get the tunnels and tracks and etc. made, collapses or flooding or other injury-i

They were also able to pay peanuts to send humans into harrowing situations to get the tunnels and tracks and etc. made, collapses or flooding or other injury-inducing hells be damned. America does build infrastructure painfully slowly and bureaucratically, but I don't think we're ever getting the early-1900s esque speed of building back at a price public entities will pay (or a price private entities could ever realisticlaly recoup). Enough rules have been written in blood to ensure that.