"The good news for us (after American dropped the hub) was that eventually we were able to provide a better carrier mix at the airport," Mineta San Jose International Airport spokesman Fernando Pena said. "One of the low-fare carriers came in and added a bunch of flights, and that was Southwest."

Passenger counts show that San Jose's airport has grown substantially. In the early to mid-1990s, when San Jose was a hub, its passenger counts hovered around 7 million yearly. In 2002 — after roughly seven years of not being a hub — the airport handled 11.1 million passengers, according to airport statistics.

In Salt Lake City, regional carriers JetBlue Airways, Southwest Airlines and St. George-based SkyWest say they will monitor what happens with Delta.

"We certainly look for markets that are underserved and will adjust our flights according to customer demand," Southwest spokeswoman Marilee McInnis said.

JetBlue spokesman Brian Baldwin said that although the airline — which is run by Utah native David Neeleman — doesn't have current plans to increase service from Salt Lake City, that could change.

"We regularly and continually monitor the industry and any changes in the industry, especially at airports we serve," he said. "So we'll be keeping an eye on that."

Life goes on

At any rate, Jeff Thredgold, economic consultant to Zions Bank and owner of 2 million Delta frequent flier miles, is sure Salt Lake consumers won't be stranded if Delta shuts down hub operations.

"If they were to close, I suspect that SkyWest (Delta's regional partner) would stay," he said. "SkyWest is profitable, and more and more flights are with SkyWest anyway.

"It's not like if Delta were to leave there'd be nothing out there. . . . Life would go on and may even become more competitive in terms of price."

Residents of Nashville weren't stranded when American left. There, Southwest gobbled up many flights that American abandoned, said Raul Regalado, president and CEO of the Nashville International Airport.

As a result, fares have come way down. For example, a recent Wall Street Journal report found the average one-way domestic fare out of Nashville International Airport was $138 in the second quarter of last year. By comparison, in Cincinnati, a major Delta hub, the average domestic one-way fare was $236 — $98 more — based on U.S. Department of Transportation data. (On Thursday, Delta said it will reduce fares by as much as 60 percent for flights out of its Cincinnati hub.)

Regalado notes that in addition to featuring lower fares, the Nashville airport has just come off its two most profitable years.