Hurricane Sandy: 5 things to know

People look at the surf as high winds and heavy rain from Hurricane Sandy arrive in Virginia Beach, Virginia, on Sunday, October 28. A construction worker covers air vents to try to prevent the New York subway system from flooding as Hurricane Sandy approaches on Sunday. New York Gov. Andrew Cuomo announced there will be an orderly shutdown and suspension of all subway, bus and commuter rail service in response to the storm. Residents of Long Beach, New York, fill sandbags on Sunday in preparation for the storm. A satellite image from 10:10 a.m. ET on Sunday shows Hurricane Sandy in the Atlantic Ocean grazing the East Coast. The storm is expected to cause massive flooding and widespread power outages when it hits the East Coast late Sunday and into the week. A man surfs at Rockaway Beach in Queens, New York, as Hurricane Sandy approaches on Sunday. Sandy is heading up the East Coast and is forecast to make a possible first landfall near the Delaware coast. Scott Davenport brings plywood to cover the windows at the Trump Plaza casino on the boardwalk in Atlantic City, New Jersey, on Sunday. Bob Kaege takes a measurement while boarding up a shop in Cold Spring, New Jersey, on Saturday, October 27, as Marie Jadick speaks on the telephone getting an updated weather report in preparation for Hurricane Sandy. Houses are flooded out in the neighborhood of La Javilla in Santo Domingo, the capital of Dominican Republic, on Friday, October 26. Residents watch firefighters battle a blaze in Kingston, Jamaica, on Friday. The fire, which destroyed the home, was started by a faulty generator that was triggered when Sandy caused a blackout, firefighters said. A motorcyclist rides through a flooded street Friday in Petit-Goâve, Haiti, where three overflowing rivers put homes and farms underwater. Corey Hutterli works on securing his sailboat as the outer bands of Hurricane Sandy are felt in Miami Beach, Florida, on Thursday, October 25. A woman stands at the entrance of her house surrounded by flood water after heavy rains in Santo Domingo, Dominican Republic, on Thursday. People walk on a flooded street after Hurricane Sandy hit Port Au Prince, Haiti, on Thursday. Burt Myrich boards up a home in preparation for Hurricane Sandy on Saturday, October 27, in Cape May, New Jersey. New Jersey Gov. Chris Christie has ordered mandatory evacuations of the barrier islands by 4 p.m. Sunday, including the Atlantic City casinos, as Hurricane Sandy threatens the East Coast. A woman peers out the door of her house Thursday after it was damaged by Hurricane Sandy in Bayamo, Cuba. A man clears debris from his house on Thursday. It was demolished by Hurricane Sandy in Santiago de Cuba. Residents in Bayamo, Cuba, try to fix a house damaged by hurricane Sandy on Thursday. A U.N. peacekeeper on Thursday stands at the edge of a bridge that was washed away by heavy rains from Hurricane Sandy in Port-au-Prince, Haiti. A house ruined by heavy flooding from Hurricane Sandy sits abandoned in Port-au-Prince, Haiti, on Thursday. Men deal with downed tree branches after heavy rains caused by Hurricane Sandy in Kingston, Jamaica, on Wednesday, October 24. Students walk in floodwater from Hurricane Sandy's rain in Santo Domingo, Dominican Republic, on Wednesday. Citizens of Bayamo, Cuba, buy food on Wednesday, as they prepare for the arrival of Hurricane Sandy. Waves hit the coast in Santo Domingo, Dominican Republic, on Wednesday. Citizens of Bayamo, Cuba, talk on the sidewalk on Wednesday. People in Bayamo, Cuba, hold umbrellas as they purchase food Wednesday before the arrival of the hurricane. Jamaicans shelter themselves from the rain of approaching Hurricane Sandy as they walk along the Hope River on Wednesday. The Hope River begins to swell with rain from approaching Hurricane Sandy in Kingston, Jamaica, on Wednesday. Houses sit along the Hope River in Kingston, Jamaica, on Wednesday. A satellite view shows Hurricane Sandy's position on Wednesday. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 (CNN) -- CNN is covering preparations up and down the eastern seaboard as Hurricane Sandy threatens to bring "superstorm" conditions. Here are five things to know: When's it going to hit? Sandy's center is expected to be near the coast Monday night, the National Hurricane Center said. It may strengthen a bit before weakening as it moves over land. For the latest details, follow the CNN Just In blog. Who's in danger? Millions of people live in areas that could see flooding, the National Hurricane Center says. From South Carolina all the way up to Maine, people are being warned to prepare -- and, in some cases, evacuate. See details here. How should people prepare? Shuttering or boarding windows and doors and bringing items in from the outside are only the beginning. You should also prepare your refrigerator, fill a bathtub with water, make sure your car's tank is full of gas, and take other critical steps. CNN provides a list here. What is my state doing? State and local officials are announcing new steps by the hour. CNN is keeping a running list here. What about transportation? Subways, buses, trains and more are being shut down in various places as the storm approaches. CNN is covering that here and in the Just In blog.