The New York Stock Exchange will close its trading floor Monday, the first time it has done so since the Sept. 11, 2001, terror attacks, joining other businesses along the East Coast altering their routine because of Hurricane Sandy.

Trading in all securities listed on the Big Board will take place through Arca, an electronic trading platform operated by New York Stock Exchange parent NYSE Euronext which operates the Big Board, the company said.

'To be quite frank, I didn't think it was that tough a decision,' said Duncan L. Niederauer, chief executive of NYSE Euronext. 'I think it would have been irresponsible to keep the building open and insist that all our people be there.'

Trading on the NYSE floor was suspended for four days after the Sept. 11 attacks. It also was suspended on Sept. 27, 1985, due to Hurricane Gloria, which caused an estimated $1 billion in damage along the East Coast.

Big U.S. banks and tens of thousands of their New York metropolitan-area employees also were preparing for disruption to start the workweek, especially in light of a shutdown of the city's transit system.

Home improvement retailers Home Depot Inc. and Lowe's Cos. began prepping for the aftermath of the storm, sending truckloads of generators, water and batteries into warehouses and stores along the Eastern Seaboard. In some Lowe's stores, customers had bought all the generators off the shelves.

The company said it would expedite extra supplies, including extension cords, snow shovels, ice melt, batteries and flashlights.Wal-Mart Stores Inc., said Sunday that it was restocking bottled water as customers empty the shelves ahead of the storm. The company expects to close half a dozen of its stores in Sandy's path.

Home Depot said it was keeping stores open late and is already in touch with the Red Cross to provide help now with things like sandbags and tarps.

On Sunday, companies with operations in New York's Lower Manhattan, including American Express Co., J.P. Morgan Chase & Co. and Citigroup Inc., were planning to close offices, prepare locations outside the city and accommodate customers affected by the storm. Others, including Goldman Sachs Group Inc. and Wells Fargo & Co., emphasized the need for workers to exercise caution and to be on the lookout for updates from managers.

Capital One Financial Corp. decided late Sunday to keep all its 350 branches in New York and New Jersey closed on Monday in anticipation of Hurricane Sandy.

'Decisions regarding closings and reopenings of branches and other business operations are based mainly on safety considerations,' said a spokeswoman for the Mclean, Va.-based bank.

Some bankers and traders, meanwhile, were resigned to working at home for a day or more. 'It sounds like it's going to be really, really bad,' said Barry Ridings, a veteran Lazard Ltd. banker who advises companies on bankruptcies and other balance-sheet restructuring deals. 'Since the trains aren't running, obviously people should stay home. I'm going to be working at home.'