Braxton Southwick is convinced a weaponized smallpox terrorist attack, or something similarly horrible, is inevitable.

He's read Revelations. He watches news about nuclear saber rattling, financial meltdowns, mega-storms rendering populations helpless for days. He is 40, and his research has led him to believe a biological attack "will happen in my lifetime."

Terrorists, he says, "would like to get a nuclear weapon, but I'm sure they'd take a pint of smallpox."

So Southwick and his wife, Kara, also 40, and their six children, ages 13-21, have stored 700 pounds of flour, 600 pounds of sugar, 800 pounds of wheat, water, gas, diesel fuel, chemical suits, coal, charcoal, 14 guns and eight chickens. They're ready to haul it in trucks and trailers to a cabin redoubt 90 minutes from their home in the West Jordan suburb of Salt Lake City if calamity hits.

They are part of a burgeoning "prepper" movement that believes preparing for the end of civilization is more rational than ridiculing those who do. Once viewed largely as a practice by survivalists on the fringe, prepping has achieved cohesion and community in the Internet age through best-selling writers, bloggers, risk assessors, conspiracy theorists and companies that cater to preppers' needs.

The number of preppers is unknown, but a poll done for National Geographic Channel in September indicated that 28% of Americans knew one. Preppers meet-up networks are proliferating on social networks. Doomsday Preppers is the network's most-watched series, and the Southwicks are featured in the series premiere Tuesday night.

Getting ready for the end is not new, of course, or strictly American. Recall how people across the USA dug fallout shelters during the Cold War. Doomsday prophets have been around as long as civilization. The federal government was the ultimate prepper during the Cold War.

One of that era's icons remains - a massive underground bunker designed to protect all 535 members of Congress and their aides against nuclear war. Dug into the Allegheny Mountains at the Greenbrier resort in White Sulphur Springs, W.Va., it once had 75,000 gallons of water, a power system, medical and food services, 30-ton blast doors, art of the last days of Pompeii and a mural of Washington scenery that was capable of changing leaves on the trees, depending on the season.

After its cover was blown by a story in The Washington Post in 1992, the bunker was abandoned by the government as an emergency destination.

Almost 10 years later, the chaos of 9/11 prompted further calls for doomsday contingencies to protect the nation's leaders and sustain the government.

You can tour this slice of underground history today. After the Southwicks visited the bunker recently, they said they felt even more strongly about the need to prepare. Their family reflects a new preparedness instinct that has been growing since the 9/11 terrorist attacks. After that shock, the government urged people to store food, buy duct tape and roll water barrels into their basements.

Some went further.

Shelter builders saw a flurry of business right after 9/11, again after the financial meltdown in 2008, and in 2010, when predictions of a Dec. 21 end of the world - derived from interpretations of a Mayan calendar - hit popular culture.

Skeptics question movement

John Hoopes, a University of Kansas anthropologist and archaeologist, has spent much time debunking the Mayan end-of-the-world predictions, arguing they are "contemporary hype ... invented by our culture and promoted by the mass media." He blames, in part, a junk-science hangover from the psychedelic drug culture of the 1960s.

Although it is prudent to prepare for storms or power outages, Hoopes says, going underground based on predictions from a long-vanished culture is simply irrational. As for the prepper movement, he urges perspective. There have always been storms and earthquakes and threats from the unknown, he says - they just weren't tweeted in real time.

Kenneth Rose, a University of California-Chico professor and author of One Nation Underground: The Fallout Shelter in American Culture, says the prepper movement raises "neighbor vs. neighbor" scenarios and "troubling class issues."

"Will the well-to-do only be able to afford these types of activities?" he asks.

"Frankly, I think people should put their energy into making a more peaceful world, rather than contemplating saving their own skins," Rose says, adding that there is "no threat now that compares with the threat of nuclear annihilation" during the Cold War.

Preppers don't buy that. Jay Blevins, a former deputy sheriff and SWAT officer in Berryville, Va., says social unrest from a financial meltdown could be devastating. He has formed a prepper network of family and friends, people with varying skills such as knifemaking. They'd help one another in such a calamity. He says his Christian faith drives him to help others prepare, and although he is not certain the end is near, he thinks getting prepared is an act of personal responsibility.

"We watch and pray," he says of his family's view toward doomsday scenarios.

Some preppers have considered ramping up efforts since President Obama's re-election last week, convinced it means the economy will soon collapse in a cascade of debt. Some are convinced Iran or another enemy is developing an electromagnetic pulse weapon that would wipe out the power, communication and transportation grids, rendering useless any device with a microchip.

Like the Southwicks - he a mechanic and former professional bike racer, she an employee of a financial company - some preppers live normal lives on the surface. Underneath, they are prepared to live in a world apart.

The Southwicks are part of a seven-family neighborhood group that vacations together and makes doomsday plans together. The neighbors know they can camp out at the cabin, Braxton says.

Others featured on Doomsday Preppers are more out there - literally. Robert and Debbie Earl, retired Florida chicken farmers, worry about the seas rising. So they are building a home constructed of old tires and sand-filled bottles near Alpine, Texas. Robert Earl describes himself as "Mad Max meets Rube Goldberg with a little bit of Al Gore thrown in."

A vulnerable world

A veritable industry has sprung up around the prepper movement. James Rawles, author of the non-fiction book How to Survive the End of the World as We Know It and a pair of best-selling novels on survival, says 130,000 people regularly read his survivalblog.com, where he and numerous contributors provide tips on how to prepare. The former Army intelligence officer has 40 advertisers selling everything from seeds to silver, and 30 more advertisers on a waiting list.

"It's a growing recognition we live in a very fragile, very interdependent society, with long chains of supply and an increasing dependence on the power grid," says Rawles, who won't say where he lives. "That dependence increases every passing year, and the vulnerability of the infrastructure to technological destruction increases by the year."

He says Superstorm Sandy's devastating impact on the populous Northeast ought to make the need for prepping obvious.

"If anybody had any doubts, if anybody was teasing their neighbors before Sandy" for storing food or preparing a "bugout bag" of essentials, he says, "they are not doing that anymore."

The day after Obama was re-elected, Rowles posted, "Several readers have written to ask me if I plan to stock up on more ammunition and magazines, now that the gun grabbers have further cemented their hold on Washington, D.C. My answer: No. I already have lots of ammunition and magazines."

The business of prepping

Scott Hunt, who co-founded a South Carolina company called Practical Preppers, says phone calls from potential customers increased the day after Election Day. "I am not going to make that correlation," Hunt says, "but you can."

Twenty months ago, Hunt, an engineer, and Dave Kobler, a military veteran, started Practical Preppers to advise people how to stockpile and defend their homes.

Business for Hardened Structures, an engineering firm based in Virginia Beach, is up roughly 40% since 2005, co-owner Brian Camden says. Some of his clients buy gold and silver and other precious metals as a hedge against a possible collapse of the currency, and they want to be able to protect it and their families, he says. So his company designs ways to build underground bunkers, strengthen walls and improve security systems on homes.

Camden says he thinks a grid-destroying electromagnetic pulse from a solar flare is the most likely threat but "after interviewing clients for 20 years, the one thing I do know is no one knows for sure what will happen."

"The rise of al-Qaeda, Islamic terrorism, political divisions here in the U.S., the rich getting richer, the separation of the economic classes," he says, describing what drives customers to him. "At the end of the day, it is asset protection. Most people identify their family as their most important asset. This is a family insurance policy."

The Southwicks sure see it that way. Braxton says his Christian faith turned him into an evangelist, urging people to prepare.

Braxton wrote a book, A Letter to My Friends, that includes the basics he preaches: Have emergency food and water in your home, have a "bugout bag" for every person that includes water, food, clothes, a thumb drive of your financial and other vital information, and other essentials.

Kara Southwick portrays herself as "more of a realist" and is not convinced that the threats are as dire as her husband portrays them. But, she says, "We prepare for everything."

USA Today