If you have an allergy, there could be a small chance that a bee sting will kill you. For the bee, though, there's no such thing as a small chance. If it stings you, it's dead. Simple as that. The stinger has small barbs on it which get stuck in any mammal with relatively thick skin, meaning that the barb is impossible to remove. As the bee is trying to fly away, then, the whole stinger tears from its abdomen and causes a lethal rupture.
It's a phenomenon equal parts sad and fascinating. Because the speed at which bees sting you, though, and the close to random nature of attacks, few people have ever caught this moment when the bee essentially kills itself by flying away. This photo shows one of those moments. Within a minute or two, this bee will be dead. Tragic, isn't it?