The IRT (Interborough Rapid Transit) was originally a private company. Thanks to the city government forcing them and rival BMT (Brooklyn-Manhattan Transit) to hold their fares down to 5¢ literally for decades, as well as “competing” against them with the cynically-named “Independent Subway” (IND), they were bankrupted after WWII with the city achieving their goal of taking them over.
Same thing happened, exactly, to the Black Ball Ferry system, not the Mosquito Fleet, when Washington State started going all socialist in 1951. The state refused to a rate increase, forcing the owner to sell the majority cross Puget Sound routes, to the state of Washington and was “allowed” to negotiate and maintain several international routes.
The Black Ball Ferry System still serve Canada and several Soviet of Washington port cities and is celebrating its 205th year of ferry business.