Increasing worries about China's economy and rising tensions over Ukraine rattled the stock market Thursday.
Investors sold stocks and shifted to safer assets like bonds. The Dow Jones industrial average fell more than 200 points and Treasury prices rose.
It was the worst day for the market in six weeks and the fourth loss in a row for the Dow. The plunge was a sharp contrast to the relatively quiet trading Monday through Wednesday following a record-setting run last week.
"The data out of China has been weak. The retail sector in America seems to be a total disaster. It's enough, combined with what's going on in Ukraine, to get people a little bit nervous and sell," said Ian Winer, director of trading at Wedbush Securities.
The Dow Jones industrial average slid 231.19 points, or 1.4 percent, to 16,108.89. The S&P 500 index fell 21.86 points, or 1.2 percent, to close at 1,846.34. The Nasdaq composite dropped 62.91 points, or 1.5 percent, to 4,260.42.
The last time the market had a bigger decline was Feb. 3, when the Dow sank 326 points, or 2.1 percent.
Thursday's slide erased the S&P 500 index's gains for the year and extended the Dow's year-to-date loss to 2.8 percent. The Nasdaq is still up 2 percent so far this year.
Nine of the 10 sectors in the S&P 500 index fell. The technology sector lost the most. Utilities bucked the trend, rising 0.9 percent. Investors tend to buy those stocks when they want to reduce risk and hold stable companies that pay steady dividends.
Bond prices rose as traders sought safety. The yield on the 10-year Treasury note declined to 2.65 percent from 2.73 percent a day earlier as bond prices rose.
Concerns over China worsened Thursday after government figures there showed industrial production rose in the first two months of the year at a rate that was lower than analysts were expecting. Retail sales growth also fell short of estimates.
"At this stage, investors are linking these negative data points coming out of China and they don't like what they see," said Lawrence Creatura, a portfolio manager at Federated Investors. "Even small hiccups there can have large implications for investors."
Stocks rose slightly in the early going, then turned lower in late morning trading after President Barack Obama issued remarks after meeting with Ukraine's new prime minister at the White House. Obama said that if Russia continues an aggressive path in Ukraine, the United States and other countries will be "forced to apply costs" to Moscow.
Citizens in the Ukrainian region of Crimea are set to vote on joining Russia on Sunday. The U.S. and European Union say the referendum violates Ukraine's constitution and international law. Russia has said it will respect the results.
Secretary of State John Kerry told a Senate committee on Thursday that Moscow should expect the U.S. and Europe to take measures against it should Russia act on a vote by Crimea to join Russia.
"The hardening of the rhetoric in these communications is a change," Creatura said.
Winer said that investors weren't panicked.
"The selling is pretty complacent," he said. "This is more about how people are positioned in the market."
In corporate news, Dollar General fell $1.63, or 3 percent, to $57.66 after the company reported that its fourth-quarter earnings took a hit from harsh winter storms. It also issued a poor outlook for the year. Other retailers have also reported weaker sales because of the extreme winter weather.
Several companies that provide oil and gas offshore drilling services fell.
Diamond Offshore Drilling fell $1.99, or 4.3 percent, to $44.39, while Noble Corp. shed $1.38, or 4.5 percent, to $28.98. Transocean lost $1.25, or 3.1 percent, to $39.54, and National Oilwell Varco slid $2.13, or 2.8 percent, to $75.18.
Investors received some encouraging news on the U.S. employment picture. The government reported that applications for unemployment benefits dropped 9,000 last week to 315,000. Applications are a rough proxy for layoffs. The declines indicate companies are confident enough about the economy to keep their staffs.