What is the chance of dying while getting a breast reduction?

Safety is the number one priority!
The chances of dying during a breast reduction surgery are very low, especially for someone who is healthy. In fact, the risk of death from surgery is far less than the risk of being involved in a car accident. While general anesthesia always carries some inherent risk, it is extremely rare for any major complications to occur, especially in healthy patients. It's important to remember that surgeons and anesthesiologists take every precaution to ensure your safety during the procedure. Typically, before any elective surgery, you'll be asked to undergo a physical examination, lab tests, and possibly an EKG to ensure you are healthy enough for the procedure.
Breast reduction is a routine, safe procedure with very low complication rates, and the benefits such as relieving back pain, improving mobility, and boosting self-esteem can significantly improve your quality of life.
If you have anxiety, it's a good idea to discuss your concerns with both your surgeon and anesthesiologist so you feel reassured and confident going into the surgery.
Best wishes!
Krishna Vyas, MD, PhD, MHSHarvard, Hopkins, & Mayo Clinic Trained Aesthetic Plastic SurgeonNew York, New York

Very unlikely, but not zero. I always tell patients that surgery is a lot like driving a car. Every time your drive your car, you could get in a terrible car accident, but it isn't something that you worry about. You put on your seat belt, make sure your brakes are working, and drive your car. Surgery is very much the same way. We take all the precautions to keep your safe and make sure you are otherwise healthy, but every surgery carries some risk.

Speaking in generalities and not knowing any medical history, the risk of general anesthesia is very low. So low, in fact, that most women are at a higher risk of death from a motor vehicle collision on the way to surgery in the morning than while under general anesthesia. While having surgery is always scary, in my opinion you should not forego surgery that will greatly and positively impact your life only to avoid extremely unlikely anesthetic or surgical complications.