Across the United States, brilliant fireworks displays will ring in the New Year in just a few days, but few people know what it takes to bring those incredible displays to life. Among those select individuals is Shelby Smotherman, a fireworks technician in Tampa, Florida, who has worked at some of Central Florida’s biggest theme parks, helping to orchestrate their fireworks shows. More than most, Smotherman knows that beyond the sparkle and glamour, a steady threat of danger lurks—when you’re dealing with literal tons of explosives, even the smallest mistake can be fatal.

Three years ago, a peculiar situation in a zoo theme park could have turned deadly. Smotherman and the other members of the firework technical crew were on an isolated island inside the park’s lake, setting up for that night’s show. It was a hot, summer afternoon. Their park-staff radio squawked more than normal, but they didn’t pay attention. The announcements usually weren’t for them.

It took one of the techs venturing off the island for the crew to learn what was going on—when the tech had reached the mainland, he found the park’s main street eerily empty. It wasn’t long before a security guard stopped him. “It’s a code zebra,” he reported back to the crew. An animal was loose in the park. Security had evacuated the park guests, but the pyrotechnicians had to stay where they were.

“We couldn’t leave the pyrotechnics alone,” Smotherman explained to ServiceMax. The technicians had already started to load, so the explosives were live and very dangerous. They had no choice but to sit tight. Large-scale pyrotechnic displays like the ones Smotherman works within theme parks are quite different from the low-powered fireworks we might set off in our backyards. So how do they work, and why is it virtually impossible to shut them down while they’re in motion? 

A Well-Orchestrated Display

At a theme park or another massive fireworks display, technicians control shows from a computerized display, and no one is running under the fireworks with a torch to set each one off at the right time. During the setup for a show, technicians build support boxes out of plywood and PVC pipes. These boxes are placed in an isolated area. Some theme parks have dedicated locations, such as islands or boats, to use for pyrotechnic launch sites. Smaller parks or businesses operating a limited-run pyrotechnic display typically place their launch sites on top of parking garages or in other locations that are less accessible to the general public.

To arrange the fireworks correctly, technicians follow instructions on a sheet much like a theatrical script, which will guide them on the angling of the explosives in the PVC pipes, the types of fireworks to use, and the pattern of their placement. Setting up a fireworks display is more than just following instructions. Weather can be fickle, so technicians know to check weather forecasts before setup and make adjustments for wind and other predictable factors. For Smotherman, this is one of many ways that working with pyrotechnics brings science and art together.

A rail like a circuit board controls the show. The fireworks themselves are set off by electronic matches, controlled from a safe distance. Each firework contains its own electronic match, which is made of a zirconium compound that ignites when hot. Wires run from the rail to the box, where, inside each firework shell, they wrap around the match. Some displays run on a computerized code that uses specialized pyrotechnic software, while others control panels are less advanced and look more like a switchboard than a modern computer.

The aerial shells themselves are preloaded with certain patterns, which are made from the arrangement of pellets inside the shell casing. Technicians have to understand how each type of firework will display in the sky. Every charge has to go off at exactly the right place and at exactly the right time, choreographed perfectly. The names for some of the most common patterns include chrysanthemum, maroon shell, palm, pistil, ring shell, round shell, serpentine, and willow.

With all of these explosives packed so closely together, it’s no surprise that when things go wrong at pyrotechnics shows, they can create epic chain reactions. If technicians load fireworks backward, they can ignite the other explosives nearby. A fire marshal is always on hand to prevent catastrophic situations. But technicians still practice extreme caution. Experienced techs have learned to always be on guard, to check everything twice, and never to leave the explosives unguarded, even for a second.

It’s precisely all of these processes and dangers that left Smotherman and her fellow techs guarding millions of dollars’ worth of high explosives while a situation beyond their control unfolded. Smotherman and the crew waited in the sweltering heat for an update. What kind of mysterious animal had escaped? Could it swim? Hours passed before security finally gave the crew the all-clear and informed them, after too much anticipation, that the animal had been an orangutan.

Hearing that, Smotherman was glad they stayed. “Imagine if the animal got up here [on the island] with no one around,” Smotherman said later. “It’s just an orangutan and fireworks. What could go wrong?”