Tenet's ( THC) next quarterly update could give investors a scare. Hammered by violent weather and mounting operational challenges, the big hospital chain is expected to deliver another quarterly loss when it issues results Tuesday morning. Even worse, some fear, the company could find itself unable to offer any real future guidance at all. Clearly, Hurricane Katrina has delivered an excruciating blow. The powerful storm wreaked havoc on the company's New Orleans hospitals -- including one where state prosecutors have begun questioning dozens of employees about possible "mercy killings" carried out in the hurricane's aftermath, CNN has reported. For its part, Tenet has portrayed its New Orleans employees as heroes and denied allegations of wrongdoing. Nevertheless, the situation there has already punished the company's bottom line and hit its tattered reputation. Meanwhile, Tenet has found itself nursing serious wounds in even larger markets as well. Last week, Hurricane Wilma damaged all 14 of the company's hospitals in south Florida -- where hundreds of thousands of residents remain without power a full week after the storm passed through, local media reports say, including some who may not regain electricity until Thanksgiving. That lack of power has shut down doctors' offices and left hospitals scrambling to treat huge crowds of patients in their emergency rooms, which tend to attract the uninsured patients who often fail to pay their bills. Tenet apparently faces big challenges in southern California, too. There, the company is reportedly in the process of slashing hundreds of people from its payrolls at hospitals that continue to struggle to make ends meet. Given such a broad spectrum of problems, some experts have started bracing for an especially painful update. The company's stock inched up 4 cents to $8.29 on Monday but continues to trade near recent lows.