The Houston skyline will be lit up on the Fourth of July by thousands of fireworks, but Thursday morning, hidden behind a treeline, a crew of six was hard at work, carefully arranging the explosives at The Water Works in Buffalo Bayou Park.

These rules include determining the minimum age, which ranges from 12 to 21 years old. What to know about buying legal personal fireworks, and at what age? More: Fireworks injuries were way up last year.