In "To Build a Fire", why did the second fire fail?
You would do well to read the story - this is an excellent and, in some ways, terrifying story that pits man against Nature and with Nature easily winning and showing its might and strength against the pitiful arrogance of the man. Let us remember the reason why the man is trying to light a second fire - he has fallen through thin ice and desperately and urgently needs to light a fire to dry his moccasins and shoes and socks and warm his feet. Failure to do this effectively and efficiently could result in death at worst or frostbite and amputation at best. However, the man's mistake leads to the quenching of the flames and sets off a series of cause and effects that results in the man's death:
It was his own fault, or, rather, his mistake. He should not have built the fire under the spruce tree. he should have built it in the open. But it had been easier to pull the twigs from the bush and drop them directly on the fire. Now the tree under which he had done this carried a weight of now on its boughs. No wind had blown it for weeks, and each bough was fully freighted. Each time he had pulled a twig he had communicated a slight agitation, so fare as he was concerned, but an agitation sufficient to bring about the disaster. High up in the tree one bough capsized its load of snow. This fell on the boughs beneath, capsizing them. This process continued... it grew like an avalanche, and it descended without warning upon the man and the fire, and the fire was blotted it!
Thus by taking the "easy" option and the quicker option of building a fire beneath the spruce tree, the man has ensured that the fire would be quenched by the snow that fell when he was picking up the wood from the base of the tree. Again, he has shown himself to be not wise enough to brave the dangers of Nature, and will pay the price.