FORT MILL kross@charlotteobserver.com

Many of the bright yellow shelves at the House of Fireworks sat half-empty on Thursday afternoon. The store was quiet and the lack of displayed merchandise was the only clue that just 24 hours earlier, the atmosphere in the store had been chaotic.

“Usually, we thin out at about probably 5 o’clock on the Fourth of July,” said Frawna Peterson, a manager. “People were still shopping between 9 o’clock and 10 o’clock last night. The crowd was just phenomenal.”

Just south of the state line, fireworks retailers are recovering from what they say was a long and hectic day of sales. Some store managers said they worked 15 to 18 hours on what is traditionally biggest day of the year for the American fireworks industry.

Some fireworks retailers make as much as 80 percent of their total sales for the year during the Fourth of July season, according to the American Pyrotechnics Association.

“That’s what you rely on,” Peterson said. “That’s how you stay in business all year.”

Peterson said the store’s Fourth of July sales this year were better than in the past two and were closer to pre-recession levels.

Customers spent anywhere from $3.95 to thousands of dollars, Peterson said.

In North Carolina it is illegal to set off fireworks that “explode, spin, leave the ground or fly through the air,” according to the City of Charlotte website. South Carolina’s laws governing fireworks are less stringent.

Peterson said House of Fireworks has many repeat customers from both Carolinas and other states as well.

One man, who did not want to give his name, purchased about $370 worth of fireworks from the store Thursday afternoon. The Georgia man said he had been coming to House of Fireworks for seven or eight years and this year’s was the biggest purchase he’d ever made. He was taking his haul to a family reunion in Pennsylvania.

Across the street from the House of Fireworks is Red Rocket Fireworks, owned by Kansas-based Winco Fireworks International.

To deal with demand, Red Rocket began keeping its doors open 24 hours a few days before the holiday, said Kim Pyles, a manager.

U.S. fireworks industry sales numbers for this Fourth of July season won’t be available for some time, said Julie Heckman, executive director of the American Pyrotechnics Association. But she predicts revenue will be up from last year.

Fireworks industry revenue from consumer fireworks products has increased every year since 1998, according to data from the association. Heckman said the fireworks industry overall saw little impact from the recession.

Revenue from sales of consumer fireworks products in 2011 was $649 million. Total industry revenue, which also includes sales of display fireworks products, was $967 million.

Opinions were mixed about whether the holiday falling on a Wednesday this year, sandwiched between two weekends, would help or hurt sales.

“July Fourth is crazy regardless of what day of the week it falls on,” said Heckman.