Having gastric bypass weight loss surgery is pretty safe as long as you're overall health is okay before you have the gastric bypass weight loss surgery.
Still anything can happen and you could die after having gastric bypass although it's rare.
The chances of dying after having gastric bypass weight loss surgery is pretty low and I would not worry about it although just be sure you want to risk the surgery.
As to the actual chance of dying from gastric bypass surgery only 1.9% of patients who underwent gastric bypass weight loss surgery died within 30 days of having the surgery.
So it's pretty safe to have gastric bypass surgery although make sure you really want to risk it before going through with the gastric bypass.