How does malaria cause death?

Several ways. Falciparum causes the organism-bearing red cells to stick together and sludge in the brain. Rapid destruction of red cells at the same time can make you anemic enough to cause death, or kill you by elevation the blood potassium, or freed hemoglobin shutting down the kidneys. A variety of more subtle mechanisms can also kill. Malaria is a neglected killer especially of the world's children.