Imagine that two days before the crash, something happened to the right engine on the plane causing it to lose power. There were loud bangs, fire came from the engine, and the pilot announced that they would have to return to the airport - but the plane continued on after the engine was restarted. Imagine, though, that permanent damage was done to the engine.
Imagine that if the right engine had been properly repaired, the flight could have continued with only one engine and would not have had to "land" in the Hudson River.
Would your opinion of a potential lawsuit against US Airways be different?