@Walt (and others) - And yet some people are wondering why airlines continue to go bankrupt...
USD 99.00 TATL fares are not sustainable for any carrier. Norwegian thought (foolishly) that they could come into a market with dirt cheap fares to stimulate demand and then be able to somehow sustain their operation long-term.
Fools and their money. It's one thing to try this stunt in an "orphan market" with little to no major carrier competition. But coming into a place that's already extremely well-served like SFO is only being asked to have your ass handed to you on a silver platter.
In the case of Norwegian; dinner has been served.