https://www.voanews.com/a/us-justice-department-sues-over-baltimore-bridge-collapse-and-seeks-100-million-in-cleanup-costs-/7789092.html
The lawsuit filed in Maryland alleges that the electrical and mechanical systems on the ship, the Dali, were improperly maintained
So how does this work with another country. Sure the US can say they owe money but how do they collect?
Other than seizing assets in the US, as someone else mentioned, there are methods for international collections.
It's a very different case, but if you go read the website of the CJIB, the Dutch Central Fine Collection Agency, they say that if you are a foreigner who gets a speeding ticket in the Netherlands, and you don't pay expecting to avoid being charged as you don't have any financial presence there, they will just go to Belgium as they own SWIFT, and quite literally just debit your bank account in your country directly without needing the consent of any other party, including you, your bank or your country.
Similarly, remember the Kim Dotcom case, where the guy expected to avoid the RIAA by doing his piracy in a country where it was technically legal, and the FBI still raided his home in a way that was technically massively illegal?
When there is a will, there is a way. On the other hand, the US does not like to bother corps though.