Wall Street declines with energy, materials, caution before Fed

Investors were also anxious as the Federal Open Market Committee kicked off its meeting, which will be followed by a statement from Chair Janet Yellen Wednesday afternoon. "People are waiting for the Fed to provide some degree of clarity going forward," said Michael O'Rourke, chief market strategist at JonesTrading in Greenwich, Connecticut. At 12:32 p.m., the Dow Jones industrial average fell 158.98 points, or 0.88 percent, to 17,818.44, the S&P 500 lost 11.95 points, or 0.57