Nine U.S. states have declared states of emergency as Hurricane Sandy bears down on the East Coast.

The U.S. National Hurricane Center said on Monday the Category 1 storm had strengthened as it turned toward the coast and was moving at 20 mph. It was expected to bring a "life-threatening storm surge," coastal hurricane winds and heavy snow in the Appalachian Mountains, the NHC said.

In preparation, thousands along the coast have been moving to higher ground and boarding up their homes and businesses. Public transportation shut down, and the U.S. stock market suffered its first weather-related closure in 27 years.

Click "next" to catch a glimpse of conditions on the East Coast as residents prepare for Hurricane Sandy.

Rough surf of the Atlantic Ocean breaks over the beach and across Beach Ave. in Cape May, N.J. on Monday morning, Oct. 29, 2012, as high tide and Hurricane Sandy begin to arrive.

(AP Photo/Mel Evans)

A truck backs up hastily as rough surf of the Atlantic Ocean breaks over the beach and across Beach Ave. in Cape May, N.J.

(AP Photo/Mel Evans)

Alix Brignol of New York takes a picture as water washes over the sea wall near high tide at Battery Park in New York on Monday as Hurricane Sandy approaches the East Coast.

(AP Photo/Craig Ruttle)

Police and firefighters respond to a downed street light on FDR drive Monday in New York.

(AP Photo/John Minchillo)

With only a security officer in the station, sandbags block the entry to the closed Staten Island Ferry in New York on Monday. All public transportation has been shut down as Hurricane Sandy approaches the East Coast.

(AP Photo/Craig Ruttle)

Asha Suckenney, 6, runs from storm surge as winds from Hurricane Sandy reach Seaside Park in Bridgeport, Conn. on Monday.

(AP Photo/Jessica Hill)

Lamar Chambers watches waves as winds from Hurricane Sandy reach Seaside Park in Bridgeport, Conn. on Monday.

(AP Photo/Jessica Hill)

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