Get your Timing Belt and Accessory Drive Belt professionally checked every 25,000 miles to make sure they are in working order. A broken belt is always bad news because when it snaps, all drive power to whatever it turns is lost. That means the water pump quits circulating coolant through the engine, the alternator quits producing amps, the power steering pump ceases to assist steering, and the air conditioner quits cooling. Many newer vehicles have a single serpentine belt that drives all of the engine's accessories, so when it fails everything stops working.
The good news is that replacing the belts periodically can go a long way towards minimizing the risk of a breakdown caused by belt failure. After all, it's a lot easier to replace a belt at your convenience than having the belt fail unexpectedly.