NEW YORK - (AP) - Stock prices hurtled lower Monday as anxietyovertook investors on the first trading day since Standard & Poor'sdowngraded American debt. The Dow Jones industrials were brieflydown more than 600 points.

The Dow fell below 11,000 for the first time since November. Thesharp drop extended Wall Street's almost uninterrupted declinesince late July, when the Dow was flirting with 13,000.

Investors worried about the slowing U.S. economy, escalatingdebt problems threatening Europe and the prospect that fear in themarkets would reinforce itself, as it did during the financialcrisis in the fall of 2008.

They desperately looked for safe places to put their money andsettled on U.S. government debt - even though those were thetargets of the downgrade Friday, when S&P removed the United Statesfrom its list of the lowest-risk countries.

The price of Treasurys rose, and yields, which move in theopposite direction from price, fell. The yield on the 10-yearTreasury note fell to 2.33 percent from 2.57 percent Friday.

"This is largely a flight to safety," said Thomas Simons,money market economist with Jefferies & Co. "The bond market isreally trading off of what's going on in the stock market."

Gold set a new record, trading for more than $1,700 an ounce.

The stock market plunged at the opening bell, with the Dow down250 points in minutes. Stocks steadily fell for most of the rest ofthe morning and early afternoon, and the Dow was briefly down 600at about 2:30 p.m.