Well it's not one of the most dangerous surgeries out there, no. But yes, there is some (small) risk of death, as with all surgeries. For breast implants roughly one in every 10-30,000 patients will die during the surgery, depending on who is doing the counting. There are also other non-death risks that can happen, some of which are severe. A responsible surgeon will fully inform you of all of these risks, and decline to perform an elective procedure like implants if they cannot do it with the absolute highest possible safety.