Can mussels kill you?
Keeping this in consideration, can you die from eating mussels?
It has been known for a long time that consumption of mussels and other bivalve shellfish can cause poisoning in humans, with symptoms ranging from diarrhea, nausea, and vomiting to neurotoxicological effects, including paralysis and even death in extreme cases.
Beside above, what happens if you eat a dead mussel?
Mussels that do not open during cooking or that have chips or cracks on the shell may be dead. The meat of dead mussels deteriorates, increasing your risk of microorganism contamination, food poisoning, infectious disease and other health problems. Earing dead mussels can be dangerous to your health.
When cooking Mussels, there are often a few stubborn shells that don't open regardless of how long they're cooked. Traditional wisdom was to discarded these (as they may have already been dead prior to cooking), you can, however, pry them open away from the plate of food, and if they smell good, they're good to eat.