Post-hurricane dangers: What to know before returning home

People wade through floodwaters with a boat in Nichols, South Carolina, on Monday, October 10. Hurricane Matthew caused flooding and damage in the Southeast -- from Florida to North Carolina -- after slamming Haiti and other countries in the Caribbean.

Workers repair downed power lines in Daytona Beach, Florida, on October 10.

Rescue teams maneuver through floodwaters in Lumberton, North Carolina, on October 10. President Barack Obama has declared a major disaster in North Carolina and ordered federal aid to supplement state, tribal and local recovery efforts.

Floodwaters inundate a home in Lumberton on October 10.

Floodwaters surround a house in Nichols, South Carolina, on October 10.

South Carolina Gov. Nikki Haley checks flooding near Nichols on October 10.

Floodwaters surround power lines near Nichols on October 10.

Without power in the hurricane's aftermath, Missy Zinc shines a light so her husband, Shawn, can prepare steaks to grill in Hilton Head, South Carolina, on Sunday, October 9.

Anthony Writebol, left, and his cousin Melissa Hill paddle past a stranded tractor-trailer in Lumberton on October 9.

A man clings to a road sign after trying to swim out to help a stranded truck driver in Hope Mills, North Carolina, on October 9. Both were rescued.

People stop and take pictures of Highway 58, which was flooded in Nashville, North Carolina, on October 9.

Boats are pushed up among twisted docks in Hilton Head on October 9.

Rescue workers help several dogs that were trapped in homes in Pinetops, North Carolina, on October 9.

A section of Wayne Memorial Drive was washed out in Goldsboro, North Carolina.

John Tweedy wades into the swift-moving floodwaters surrounding his business in McClellanville, South Carolina, on Saturday, October 8.

A woman who gave her name only as Valerie walks along flooded President Street after leaving her homeless camp in Savannah, Georgia, on October 8.

Volunteers clear debris from from a pool at a condominium complex in Jacksonville Beach, Florida, on October 8.

A police officer steps through the remnants of a home leveled by Hurricane Matthew in the tiny beach community of Edisto Beach, South Carolina, on October 8.

A downed tree and power lines block a road on Georgia's St. Simons Island on October 8.

A woman fights the wind in Wrightsville Beach, North Carolina, on October 8.

Parts of Highway A1A in Flagler Beach, Florida, were washed away by Hurricane Matthew on Friday, October 7.

Water flows over a seawall and fills the streets of St. Augustine, Florida, on October 7.

Barbara Hearst tapes her storm shutters as Hurricane Matthew nears Charleston, South Carolina, on October 7.

Adam and Alec Selent watch waves crash over a retainer wall at the Ocean Club condominiums in Isle of Palms, South Carolina, on October 7.

A damaged boat sits partially submerged on the intercoastal waterway in Melbourne, Florida, on October 7.

A police officer helps persuade a woman to board a bus and evacuate Savannah, Georgia, on October 7.

Preston Payne tries to hold his umbrella on Georgia's Tybee Island on October 7.

Heavy waves pound boat docks in Cocoa Beach, Florida, on October 7.

A women helps a dog walk through floodwaters in Port Orange, Florida, on October 7.

Damage in Cocoa Beach.

Waves crash against a bridge in St. Augustine, Florida.

A car drives past a downed tree as the hurricane moves through Daytona Beach, Florida, on October 7.

A billboard canvas flaps in the wind after Hurricane Matthew passed North Palm Beach, Florida, on October 7.

A woman inspects her damaged car under a tree in Fort Pierce, Florida, on October 7.

A space shuttle model stands near some downed trees after Hurricane Matthew passed by Cocoa Beach.

A woman uses her phone under a battery-operated lantern at a hotel in Titusville, Florida, on October 7.

Palm trees on Cocoa Beach sway in the wind on October 7.

Firefighters respond to a pre-dawn house fire in Satellite Beach, Florida, that was possibly caused by a downed power line on October 7.

Heavy rain billows in front of Exploration Tower in Cape Canaveral, Florida, on October 7.

People stand on a beach in Broward County, Florida, as the storm approached the coast on Thursday, October 6.

A police officer walks along the beach in Singer Island, Florida, on October 6.

Kevin Forde and John Haughey put plywood on a Miami Beach window on October 6.

Hurricane Matthew moves through Paradise Island in Nassau, Bahamas, on October 6. Capt. Stephen Russell, the head of the Bahamas National Emergency Management Authority, said there were many downed trees and power lines but no reports of casualties.

People leave Disney's Magic Kingdom theme park, in heavy rain, after it closed in Orlando, Florida in preparation for the landfall of Hurricane Matthew, on October 6.

A man rakes up debris from a storm drain as he begins cleanup near a damaged gas station in Nassau on October 6.

Residents repair their homes in Les Cayes, Haiti, on October 6. The damage from Hurricane Matthew was especially brutal in southern Haiti, where sustained winds of 130 mph punished the country.

Girls hold hands as they help each other wade through a flooded street in Les Cayes on October 6.

Two days after the storm, authorities and aid workers in Haiti still lacked a clear picture of what they fear is the country's biggest disaster in years.

A supermarket shelf is nearly cleared out in Titusville, Florida, on Wednesday, October 5.

Bumper-to-bumper traffic lines Interstate 26 in Columbia, South Carolina, as people drive west on October 5.

Workers start removing umbrellas and the colorful rocking chairs that line the Cocoa Beach Pier in Cocoa Beach, Florida, on October 5.

People carry a coffin and try to cross the La Digue river on October 5 after a bridge collapsed in Petit-Goave, Haiti.

People cross the La Digue river on October 5.

Evacuees return to their homes in the Carbonera community of Guantanamo, Cuba, on October 5.

People embrace at their damaged home in Baracoa, Cuba. The hurricane rolled across the sparsely populated tip of Cuba, destroying dozens of homes in the country's easternmost city and leaving hundreds of others damaged.

A woman cries amid the rubble of her home in Baracoa.

Bus drivers in North Charleston, South Carolina, wait for word to start evacuations.