NEW YORK — Stocks plunged again Thursday as more investors woke up to the possibility that economic problems such as Europe’s debt crisis might spread around the world and stop the growing recovery in the U.S.

The Dow Jones industrial average fell 376 points, its biggest one-day point drop since February 2009, and all major indexes were down well over 3 percent. Meanwhile, interest rates fell sharply in the Treasury market as investors once again sought the safety of U.S. government debt.

With Thursday’s drop, the Standard & Poor’s 500 index, considered the best indicator of the stock market’s performance, is down almost 12 percent from its 2010 high close of 1,217.28, reached April 23. That means the market is officially in what’s called a correction, a drop of 10 percent or more from a recent high. This is the first correction since stock indexes hit 12-year lows in March last year. The fact it has occurred in just 19 trading days shows how anxious traders are right now.

Analysts said there was no big event to set off Thursday’s selling. More investors seemed to be grasping the possibility that the U.S. recovery could be in jeopardy. And many were wondering whether the stock market’s big rebound since March 2009 may not have been entirely justified.

“The economic recovery story has started to look like a mirage and the new reality is a return to credit crunch conditions” like those seen during the financial crisis, said Tom Samuels, manager of the Palantir Fund in Houston. “If that’s correct, stock prices are well ahead of economic reality.”

Investors are concerned that the debt problems in European nations like Greece and Portugal will spill over to other countries, cause a cascade of massive losses for big banks and in turn halt the economic recovery in countries beyond Europe, including the U.S. They’re also worried that China might take steps that will limit its economic growth, which would also affect the U.S. recovery.

Investors appear increasingly convinced that European countries will need to adopt stringent spending cuts to pay down their heavy debt loads, independent market analyst Edward Yardeni said. Such cuts would likely to lead to a long economic slump for those countries, a prospect that investors may now be accepting as reality as they sell stocks and the euro, the currency shared by 16 European nations, Yardeni said.

The euro, which has become a key indicator of confidence in Europe’s economy, managed to rise to $1.2496 in late afternoon trading, a day after hitting $1.2146, a four-year low. But its advance didn’t help stocks.

“The drop in the euro is the initial phase of a long-term, multi-year economic decline in Europe,” Yardeni said. “It shows a declining confidence in the workability of the EU (European Union) monetary union, and that’s why their stock markets are down.”