Science vs religion
Try and find all the scientific / evolutionary references in this movie. Math, aviation, plants, trees, air, even death.
Woods is caught. He is scientific but unable to act after the first suicude. He removes the fence (symptom not cause).
Turner is a believer - often the woman is more than the man.
They die from lack of air in the end - hanging, oven gas, car gas. They suffocate under the mother's misunderstood love.
Or they don't die - they just grow up. So the boys are infatuated with their lost innocence and youth. The virginal state.