A sell-off in U.S. stocks accelerated Wednesday, with all three major indexes ending at their lowest levels of 2011.

The S&P 500 and Nasdaq composite erased their gains for the year, while the Dow is barely hanging on, up only 0.3% in 2011.

Trading was extremely choppy as investors tried to sort out disappointing U.S. housing data against the backdrop of developments in Japan.

It didn’t help that European Union energy commissioner Günther Oettinger sounded a warning bell about increased risks related to Japan’s crippled nuclear reactors at a meeting in Brussels.

Moreover, the U.S. Embassy in Tokyo cautioned American citizens who live within 50 miles of the damaged Fukushima Daiichi nuclear plant to evacuate or take shelter indoors.

“Today’s not a good news day, and the market is reacting emotionally,” said Fred Dickson, chief market strategist at D.A. Davidson & Co.

The Dow Jones industrial average tumbled 242 points, or 2%, with all 30 components of the blue chip index in the red. The index was down almost 300 points at its low for the day.

The S&P 500 slipped 25 points, or 2%, to end at 1,256.88. The broad index closed 2010 at 1,257.64.

The Nasdaq lost 51 points, or 1.9%, to finish at 2,616.82. The tech-heavy index closed at 2,652.87 last year.

(Source: CNN Money)