Just when we all thought it couldn't get worse for the airlines, another drop in the bucket. To say the least. Apart from the human tragedy, the far-reaching devastation wrought by hurricane Katrina touched several of the major carriers Monday and appears to be on the warpath still.

Among the affected: UAL Corp's (OTC BB: UALAQ) United, AMR's (NYSE:AMR) American, Delta (NYSE:DAL), Continental (NYSE:CAL), and strike-plaguedNorthwest (NASDAQ:NWAC). Heck, pretty much anyone trying to make money shuttling passengers to and fro had a bad Monday.

Scores of flights were canceled. Continental topped the list at 111 yesterday, according to the Associated Press. United appeared to come in second with 63 flights scrubbed by mid-morning. Northwest told the AP that 29 flights were canceled and service had been suspended to 12 southeastern cities. Delta didn't give an exact number but put the total in the dozens, including service to and from nine cities in Louisiana, Mississippi, and Alabama.

With all the red ink covering the financial statements of the major carriers -- and even some of their beleaguered smaller rivals, such as Washington, D.C.-based Independence Air (NASDAQ:FLYI) -- the loss of traffic amounts to yet another drain on already limited financial resources.

And then there's oil. Windswept drilling platforms in the Gulf of Mexico have sustained enough damage to cut more than 90% of that area's crude oil production. That sent per-barrel prices briefly above $70 yesterday. They are back in that rare air today. Aside from labor, fuel is the biggest cost for carriers, and rising prices put a serious strain on profits. Even Motley Fool Stock Advisor pick JetBlue (NASDAQ:JBLU), which flies to only one city in the disaster area (New Orleans), has been affected by the skyrocketing price of fuel.

In the face of all this, airline stocks have cratered, naturally. It may be tempting for some to consider buying into the malaise under the guise of value investing. I mean, really, Delta is trading for barely more than $1 a share! But no hurricane blows powerful enough to change the economics of a bad business. And few businesses are worse than airlines. Delta, specifically, has been flirting with disaster for months. (Indeed, check the numbers for yourself.)

The very sad truth is that while Katrina has delivered the industry a terrible triumvirate in lower traffic, higher oil prices, and frustrated customers, this industry has been damaged goods for years. One or more of the major carriers was always going to go the way of the dodo. Now that day may come a little sooner.

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Fool contributor Tim Beyers didn't own shares in any of the companies mentioned at the time of publication, but members of his family are retired from United Airlines. You can find out what is in Tim's portfolio by checking his Fool profile here. The Motley Fool has an ironclad disclosure policy.