Natural gas futures crashed to a three-year low as warm weather cut demand for the heating fuel and Hurricane Joaquin threatened to prolong higher-than-average temperatures. Natural gas for November delivery fell 9.1 cents, or 3.6%, to settle at $2.433 per million British thermal units on the New York Mercantile Exchange. The last time gas closed lower was June 13, 2012, when futures slid to $2.185.