Editor's Note: Late on Wednesday, June 16, Spirit Airlines announced it had reached a tentative agreement with its striking pilots. Flights are scheduled to resume Friday, June 18.

And now for something completely similar: An airline behaving badly.

Because it is small, you may not have heard that Florida-based Spirit Airlines has been shut down since Saturday. After more than three years of negotiations and a federally mandated 30-day cooling-off period, Spirit's approximately 450 pilots walked off the job. The airline then abruptly canceled all of its 150 or so daily flights and has been grounded ever since. As of Tuesday afternoon, Spirit said service through Thursday was canceled.

But "small" is a term of art in the airline business. Spirit represents about 1 percent of the nation's commercial-aviation capacity, which translates into a not insubstantial 15,000-plus passengers a day. Since the strike began, that means around 100,000 passengers have been stranded. And stranded is the operative word, since Spirit has taken the extraordinary step of abandoning its customers wherever they last flew them, maximizing their financial and transportation pain and blithely playing just inside the regulatory margins.

Even by the fast-and-loose standards of today's airline industry, Spirit's actions during and in the run-up to the strike is startling for its insensitivity to customers and disregard for the conventions of ethical business practices. For years, Spirit has operated as the P.T. Barnum of airlines—the carrier's management believes there's a bargain-hunting sucker born every minute—but its reaction to the strike has appalled even the most cynical observers of the airline scene.

Spirit's maneuvers began last month, when the National Mediation Board released the carrier and its unhappy pilots—airline contracts never technically expire, but become "amendable"—into the cooling-off period that must precede any strike. With a 30-day clock ticking, most airlines create a "reaccommodation" policy that allows passengers in the path of a potential strike to change or cancel flights without penalty.

Spirit not only refused to formulate such a policy, it never warned existing or future customers that a strike was possible. No notice appeared on its website, and few if any customers were called or alerted by email. If a customer somehow stumbled on news of the potential strike, Spirit refused to allow any adjustments to their travel itineraries unless a change fee of $100 or more was paid.

As the strike deadline approached, Spirit began proactively canceling some flights for last weekend. That alerted some of the otherwise somnambulant beat reporters at the nation's newspapers and wire services. But rather than press Spirit chief executive Ben Baldanza or the carrier's hapless public-relations flak, the media gobbled up and regurgitated the Spirit line. The airline claimed it would fly through the pilot's strike, that it was arranging substitute flights from other carriers, and that it was making alternate arrangements for passengers with other airlines.

None of that was true, and the gullible media stenographers should have known it. No airline, of any size, has ever flown through a pilot's strike. Unlike flight attendants or even mechanics, who can be replaced by trained management employees, there aren't a lot of airline executives certified to fly aircraft. The fiction of arranging for other carriers to operate Spirit's flights? There's not a lot of free capacity in the market right now. Besides, since most pilots belong to the Air Line Pilots Association (ALPA), the strong pilot's union, the chances that other airlines would pick up Spirit's flying was slim. ALPA would (and has) branded the flying "struck work" and told its members not to fly the planes.

Spirit's claim that it was arranging to buy seats on other airlines to fly its passengers? Another easy-to-disprove claim. Spirit has no "interline" agreements with other carriers, which means it must buy tickets on the open market. If Spirit had actually bought a significant number of seats in bulk on its competitions, the information would have leaked out.

As negotiations extended into overtime—the midnight deadline last Friday was extended for five hours—Spirit still did nothing to warn its passengers either by phone or email, nor did it post any warning on its website.

When the pilots walked off the job at 5 a.m. last Saturday, Spirit simply canceled its entire schedule for the day. Passengers arrived at airports around the Americas—Spirit flies to Central and South America as well as many U.S. destinations—and were told they were on their own. No help was available, no flights were planned, and Spirit would not help flyers with their alternatives. Moreover, since Spirit has none of those interline agreements, tickets purchased on Spirit are not honored by other airlines.