Blame it on the weather.

Why else would most regional companies nosedive Monday? Perhaps investor panic over the coming snow storm triggered sell orders. Perhaps the lousy day in the stock market had something to do with political paralysis in Washington.

But one thing was certain: Of the few regional stocks that scored gains Monday, one of them was a weather play. Overland Park-based Compass Minerals, which is one of the largest sellers of highway de-icing salt, gained a dime Monday, or 0.1 percent.

The loser list, on the other hand, was lengthy. Among the noteworthy declines, Cerner fell 2.5 percent, Waddell & Reed lost 3.5 percent, Layne Christensen, lost 4.7 percent, Commerce Bancshares lost 3.3 percent, Garmin declined 2.3 percent and Sprint lost 1.6 percent. Kansas City Life fell more than 4 percent.

Overall, stocks dropped sharply as investors worried that Italy could be seized with political instability, stymieing the country's economic reforms and causing another flare-up in the region's debt crisis.

The Dow Jones industrial average plunged 216 points to 13,784 Monday, a loss of 1.6 percent and the biggest drop since November.

The Standard & Poor's 500 dropped 27 points, or 1.8 percent, to 1,487. The Nasdaq lost 45 points to 3,116.

An early gain was gone by midday after reports from Italy suggested that the country was headed for political gridlock following strong gains by former premier Silvio Berlusconi and a protest campaign led by a former comedian.

Four stocks fell for every one that rose on the New York Stock Exchange. Volume was average, 3.8 billion shares.

The BATS 1000 fell 309.00 points, or 1.81 percent, to close at 16,797.93.

Regional stocks

Capitol Federal Financial fell 9 cents, or 0.76%, to close at $11.78.

Cerner Corp. fell $2.18, or 2.49%, to close at $85.38.

Commerce Bancshares Inc. fell $1.29, or 3.33%, to close at $37.47.

Compass Minerals rose 10 cents, or 0.13%, to close at $74.90.

DST Systems Inc. fell 32 cents, or 0.47%, to close at $67.27.

Ferrellgas Partners L.P. rose 4 cents, or 0.20%, to close at $20.07.

Garmin Ltd. fell 80 cents, or 2.29%, to close at $34.20.

Great Plains Energy fell 59 cents, or 2.66%, to close at $21.55.

H&R Block Inc. fell 39 cents, or 1.58%, to close at $24.27.

Inergy L.P. fell 22 cents, or 1.12%, to close at $19.40.

Kansas City Life Insurance Co. fell $1.52, or 4.01%, to close at $36.35.

Kansas City Southern fell $2.24, or 2.27%, to close at $96.54.

Layne Christensen Co. fell $1.09, or 4.74%, to close at $21.92.

O’Reilly Automotive Inc. fell 90 cents, or 0.88%, to close at $101.35.

Sprint Nextel Corp. fell 9 cents, or 1.55%, to close at $5.73.

UMB Financial Corp. fell $1.05, or 2.27%, to close at $45.27.

Waddell & Reed Financial Corp. fell $1.48, or 3.48%, to close at $41.09.

YRC Worldwide Inc. rose 4 cents, or 0.63%, to close at $6.40.