At its peak at the end of the 19th century, the U.S. ice trade employed an estimated 90,000 people in an industry capitalized at $28 million ($660 million in 2010 terms),[a] using ice houses capable of storing up to 250,000 tons (220 million kg) each; Norway exported a million tons (910 million kg) of ice a year, drawing on a network of artificial lakes. Competition had slowly been growing, however, in the form of artificially produced plant ice and mechanically chilled facilities. Unreliable and expensive at first, plant ice began to successfully compete with natural ice in Australia and India during the 1850s and 1870s respectively, until, by the outbreak of World War I in 1914, more plant ice was being produced in the U.S. each year than naturally harvested ice. Despite a temporary increase in production in the U.S. during the war, the inter-war years saw the total collapse of the ice trade around the world. Today, ice is occasionally harvested for ice carving and ice festivals, but little remains of the 19th-century industrial network of ice houses and transport facilities.