NEW YORK ( TheStreet) -- U.S. stock markets will open Wednesday after Hurricane Sandy slammed the East Coast, flooding lower Manhattan and shuttering trading for two days. The New York Stock Exchange and Nasdaq said equity, bond, options and derivatives trading will commence as usual. It was the longest weather-related shutdown in more than 100 years. The Sept. 11, 2001, terrorist attacks closed the markets for a week. Despite widespread flooding in lower Manhattan, where Wall Street is located, the New York Stock Exchange "building and trading floor are fully operational," the NYSE said in a statement. The Nasdaq released a similar press briefing. Monday's closure marked the first time trading had been suspended for an entire day due to weather since Sept. 27, 1985, when Hurricane Gloria struck. Sandy was expected to cause about $20 billion in property damage and another $10 billion to $30 billion in lost business, according to data given to the AP by forecasting firm IHS Global Insight. President Barack Obama declared a major disaster in New York and Long Island, which bore the brunt of the sea surge from the superstorm that hit the East Coast on Monday. The president also declared major disasters in New Jersey, West Virginia and Virginia. The U.S. death toll rose to 39 following Sandy's destruction across the East Coast, according to the Associated Press. More than 8.2 million people were without power across the region. Airlines canceled over 15,000 flights around the world, and it could be days before airline companies reschedule passengers whose flights were canceled because of the storm, according to the AP. The National Hurricane Center said Tuesday the storm was moving westward across Pennsylvania and was centered about 90 miles west of Philadelphia. The storm lost its hurricane status on Monday and is now considered an extratropical cyclone. It was expected to move into western New York on Tuesday night and move into Canada on Wednesday. Weather warnings and watches remained in effect throughout much of the East Coast. Flood and coastal flood watches and warnings were in effect from the mid-Atlantic to Northeast states. Blizzard warnings remained in effect through high elevations of the central Appalachians. Obama spoke Tuesday at the Red Cross in Washington D.C. and warned Americans that the storm was not yet finished. "America is with you. We are standing behind you, and we are going to do everything we can to help you get back on your feet," the president said. As of an 11 a.m. EDT update, Sandy's maximum sustained winds were near 45 miles per hour. Lower Manhattan, where the New York Stock Exchange floor is located, was still largely without power Tuesday morning after energy company Con Edison ( ED) shut off most of the electricity in the area to protect electrical equipment from the massive storm surge of salt water caused by Sandy. In the event that there was any unexpected damage that could keep the floor closed, the NYSE had a contingency plan to make its Arca electronic market the primary market for companies listed on its exchange, according to Bloomberg. Obama will remain in Washington D.C. through Wednesday and has canceled campaign appearances for that day, his campaign told reporters in an email. Mitt Romney will resume campaign rallies on Wednesday as he makes a swing through Tampa, Coral Gables and Jacksonville -- three major Florida cities that will play a pivotal role in the election next week. Parts of two nuclear power plants were shut down late Monday and early Tuesday. One of the units at Indian Point, a plant about 45 miles north of New York City, was closed Monday because of external electrical grid issues, according to Entergy, which operates the plant. Before 8 p.m. EDT on Monday, the storm made landfall along the coast of southern New Jersey. The storm's maximum sustained winds hit 75 miles per hour and the system's movement slowed to 18 miles per hour, according to an update at 11 p.m. on Monday. It had previously been moving at 28 miles per hour before making landfall.