What does it take to put on a fireworks show big enough for the Big Apple?
Co-designer Gary Souza said organizers of the Macy's Fourth of July Fireworks 2013 -- the nation's biggest display -- scoured the world to find and purchase the most original new fireworks, from China and Portugal to Spain and Malta.
For Thursday's event, 40,000 shells will be launched from four barges off Staten Island. They were loaded over the weekend and their exact location was being kept secret for security reasons.
The barges will sit on the Hudson River for the show, to be seen by an estimated 3 million people watching live in New York and New Jersey, plus millions more on television. Grammy-award winning musician Usher created the soundtrack.
Souza said the 25-minute show's theme is "It Begins With A Spark."
The barges will be set up on the Hudson between West 24th and 42nd streets, with fireworks shooting about 1,000 feet into the air.
The plans began a year ago in Rialto, Calif., where Souza is part of the current generation of a family that runs Pyro Spectaculars by Souza.
Sixty pyrotechnicians worked on Staten Island all weekend to prepare the high-tech digital animation.
This year, a winking smiley face, a jellyfish discovered in China that explodes with a whistling sound and bursting butterflies are newcomers to the show.
From midtown Manhattan, the Empire State Building will play along, showing off its recently upgraded LED lighting along with the fireworks.
The first explosions are scheduled to go off at 9:25 p.m. Thursday.
"It looks like pyrotechnical chaos at first, then it reins itself in," said Souza, looking at the neatly lined up mortar tubes.
And despite every possible precaution taken to ensure safety, "anything can happen," he said. "It's a dangerous business."
Each year, he said, his mother has white-knuckled her way through the spectacle.
Safety is paramount, said executive producer Amy Kule.
After that, she said, "it's about how to make it as entertaining as possible, how to make it bigger and better -- playing with science and technology."