Comic from: dD in an eggroll
Blogger Alex "Sandy" Antunes wrote an article on Science 2.0 that explores which science causes the most deaths.
According to movies, physics would be the clear winner: car crashes, gunshot wounds, bicycle accidents, falling down, people hitting each other, and war are all physics-driven deaths.
Chemistry related deaths would be toxins, poisons, drugs, alcohol, or drowning.
But... biology is the deadliest. Since heart disease, cancer, and stroke kill the most people in North America, as well as disease and infection throughout the world's population.
You can read the full article here: http://www.science20.com/daytime_astronomer/which_science_kills_more_people-77520