Economically sensitive industrials Boeing Co BA.N and Caterpillar Inc CAT.N slipped 1.7% and 1.9%, respectively. By Sagarika Jaisinghani Sept 20 (Reuters) - U.S. stock index futures fell 1% on Monday, as investors worried about rising COVID-19 cases and the pace of economic growth at the start of a week in which the Federal Reserve will decide on potentially tapering its massive pandemic-era stimulus. Wall Street's main indexes have been hurt this month by fears of potentially higher corporate tax rates denting earnings and have shrugged off signs inflation might have peaked.