Editor's note: This tour of small businesses across the country highlights the imagination, diversity, and resilience of American enterprise.

Adam Corn remembers the day in 2002 when he first visited the pit at Ground Zero. It was a scene of surreal destruction: pipes leaking water, staircases leading nowhere. There he stood, seven stories underground, describing matter-of-factly to a general contractor the properties of Geofoam, the white foam blocks manufactured by his family's business, Poly Molding, in Haskell, New Jersey.

Few people have heard of Poly Molding, a company that brings in $5 million in annual sales. But every year, millions of pedestrians walk over its product. Geofoam is part of some of the region's most ambitious construction projects, including the stadiums of both of New York's Major League Baseball teams. And Poly Molding--by virtue of its location and its expertise--has played a role in the difficult rebuilding that followed the tragedies of 9/11 and Hurricane Sandy.

Corn was working as a salesman at the business when he got the World Trade Center call. Skanska, one of the largest construction companies in the world, had won 80 percent of the $542 million contract to build the site's subway station: a giant white structure called the Oculus that looks like a dinosaur skeleton. Skanska hired Poly Molding to provide five truckloads of expanded polystyrene in 100-pound blocks to be used as partial foundation for the station. Geofoam is made from the same precursor material as Styrofoam, but the finished product is slightly different.

"It's stronger than dirt, cheaper than dirt," says Corn of the product that his family has been manufacturing for 50 years at a small factory, 30 minutes from New York City. "Dirt settles and displaces. But expanded polystyrene will never biodegrade or lose its form, which is exactly what you need when you are looking for a material for a foundation. It absorbs vibration and will last centuries."

As Corn finalized the deal to provide thousands of cubic yards of foam over 12 years of construction, he took in the gravity of the situation. His foam would lie beneath the World Trade Center forever. "In my little way, I was able to work on the Freedom Tower," Corn says as he walks around his factory on a Wednesday afternoon, giant foam blocks scuttling along a conveyor belt nearby. "That was my proudest moment."

Poly Molding is not just a part of many local landmarks. It is at their very foundation.

From mannequin heads to Yankee Stadium

Corn is now the third-generation CEO and president of a business founded in 1962. His grandfather, Herbert Corn, came across expanded polystyrene during World War II, when, as a Navy engineer, he built roads in Germany. Returning to New Jersey, Herbert approached Dow Chemical, which had begun making a similar material--trademarked Styrofoam--several years earlier. Dow explained the basics of production, which were fairly simple. Determined to create his own version, Herbert came up with a manufacturing method. White plastic polystyrene pellets, the size of a few grains of sand, are loaded into a machine not unlike a giant popcorn popper. The machine--called an expander--cooks the pellets until they double in size and become soft and malleable. The expanded beads are then vacuumed up through tubes, placed in molds, and cooked until they fuse together with steam.

At first, Poly Molding used the material to make beer coolers and mannequin heads. When Herbert's son Stuart joined the business in 1965, he convinced his father to expand into residential construction--specifically, making insulation for homes. In 1989, Stuart bought the business from his father and took over as CEO.

Poly Molding is a typical family business: Its ambitions grow with each generation. Adam Corn started working in the factory in 1992 and became a salesman in 1994, when the company was still doing only small, residential projects. In 1998, Corn read an article about the years-long construction of a network of roads, highways, and overpasses in Salt Lake City to prepare for the 2002 Olympics Games. The project used expanded polystyrene for the foundation and was completed faster and more cost effectively than it would have been with soil, the conventional choice. 

Corn convinced his father that big construction projects could be a lucrative new market for the business. If Poly Molding started manufacturing 100-pound blocks of the foam, Corn would sell it aggressively. His proposition to contractors: Geofoam would save them time and thousands of dollars in equipment and construction costs. The greatest cost for the product is shipping. So Poly Molding's prime location gave it an unbeatable advantage for the large projects--of which there are no shortage--in New York City, Long Island, and New Jersey.

Still, people didn't trust the material. Corn would complete his pitch, and then the potential customer would pick up an empty Styrofoam coffee cup and pointedly crush it in one hand. Corn spent five years educating general contractors about the benefits of foam. He gave strength and resiliency plenty of emphasis.

Then came the World Trade Center job. Over the next few years, familiarity with and trust in the product grew among the building trades. In 2008, the company won a contract to provide Geofoam for the foundation of a parking garage and youth football field by the new Yankee Stadium. That same year, Poly Molding made polystyrene for the retaining wall foundation at Citi Field in Queens, home to the Mets.

In 2009, Poly Molding worked on the Jack Nicklaus-designed Trump Golf Links, at Ferry Point in the Bronx. Twenty thousand cubic yards--220 truckloads--of polystyrene was laid underneath the course to create peaks and valleys.

After the hurricane

Stuart Corn died in 2010, and Adam Corn ran the company as interim CEO until he bought the business from his mother in 2011. The new leader started out confident: His father had brought him up to speed on everything regarding the business. Or so he thought. Going through the accounts, Corn discovered that Poly Molding was almost $1 million in debt. The company was in crisis.

"If I had known beforehand...I would've sold it," Corn says.

But as owner of the business, Corn knew that, at least for the time being, selling was not an option. Some employees had been with Poly Molding for 30 years. He decided to try to keep the company running for 12 months, although he half-believed it would go under. The business made it to 2012, slowly paying back its debt. But it was not in the clear.

That summer was tough. Again, Corn entertained the idea of packing it in. He could easily sell the land, the factory, and his fleet of trucks to a competitor hungry for a prime location close to the city. By October, things were so tight Corn knew he had to wrangle significant new business or Poly Molding wouldn't make it through the end of the year.

On October 29, 2012, Hurricane Sandy struck the tri-state area. Floodwaters washed out hundreds of building foundations and ruined homes. "All of a sudden, everyone needed a new foundation," says Corn. "I hate to say it, but Superstorm Sandy saved us."

In the wake of Sandy, dozens of jobs poured in, ranging from residential homes to the substantial repairs required on Chelsea Piers, a sports complex along the Hudson River in Manhattan. Corn's sales shot up 24 percent, and Poly Molding was back on its feet.

Since then, the work hasn't let up. In 2013, Poly Molding helped with the construction of a 95,000-square-foot building for the Raritan Bay Medical Center in Old Bridge, New Jersey. Other projects include the basketball arena and another athletic building at Stony Brook University and a new road in Salem, New Jersey. Up next: the American Dream Meadowlands project in East Rutherford, New Jersey; a new mall; a network of roads; and infrastructure surrounding MetLife Stadium.

In the spring of 2013, Poly Molding provided Geofoam for the foundation of a 600-foot ramp in Staten Island leading to the Verrazano Bridge. Restani Construction Corp. was general contractor for the $50 million project. Humphrey Vincente, a civil engineer at Restani, calls Poly Molding among the best vendors with which his company has worked. "Building bridges and ramps is dangerous. Therefore you need vendors who you can trust to know what they are doing," says Vincente. "Poly Molding's knowledge of Geofoam was key for us."

A lesson in succession

Speaking from a position of success, Corn acknowledges how hard it was taking over the family business, which now employs 25 people. After Stuart Corn died, many of the suppliers with whom his father had longstanding relationships went elsewhere. Corn was forced to build a new circle of loyalty, drawing on his own relationships begun when he was a salesman.

As a salesman, "I started making friends with the forklift guys and people my age in the industry who were working up the ladder at different construction companies," says Corn. "Now, they are the ones running the companies." Those relationships "got us through after I took over. Now, they don't look at it like they're buying from Poly Molding. They're buying from Adam."

Even though those first years as CEO were tough, Corn recalls them gratefully as a period of growth.

"When your back is against the wall, you find out a lot about yourself," he says. "I'm not the smartest guy in the world. But I work as hard as anybody.

"When you're trying to get out of a hole, all you do is look down and dig," says Corn. "But once you're out of it, you look around and find out why you survived."