Stocks fell on Monday, sending benchmark indexes down more than 1 percent, as investors worried that a possible global flu outbreak could complicate efforts to revive the economy.

The CBOE Volatility Index <.VIX>, also known as Wall Street's fear gauge, rose 7 percent to 39.38.

The early sell-off was broad based, with airlines and shares of energy companies among the biggest casualties.

The Dow Jones industrial average <.DJI> was down 84.98 points, or 1.05 percent, at 7,991.31. The Standard & Poor's 500 Index <.SPX> slid 9.89 points, or 1.14 percent, at 856.34. The Nasdaq Composite Index <.IXIC> dropped 18.39 points, or 1.09 percent, at 1,675.90.

(Reporting by Edward Krudy; editing by Jeffrey Benkoe)