Tortoises can die for a number of reasons including insufficient food, poor quality diet, unsanitary conditions, stress, and untreated infections and injuries. All these can cause your pet tortoise to die.
Tortoises do not smell bad and they don’t have much of a natural odour. At most, they may smell musty or just have an outdoorsy, musky smell. However, their enclosures can sometimes become breeding grounds for bacteria and other odor-causing organisms if you don’t clean them well enough. A stinky tortoise could be a sign of infection or illness.