PHOTOS: A look inside the 7K pounds of fireworks behind Lake Union’s 4th of July celebration

SEATTLE — Around 50,000 people are expected gather at prime viewpoints around Seattle’s Lake Union for Seafair’s 4th of July fireworks show.

KIRO 7 was invited on board the floating barge staging the whole big bang show as crews were setting up on Monday. While there, we got to see 7,000 pounds of custom-made fireworks with a thousand fuses, all loaded onto a floating platform.

The planning around the computer choreography and engineering for the fireworks show starts around Christmas, as pyrotechnicians plan an 18-minute display starting at 10 p.m. on July 4.

The rhythmic boom and color will also have a special custom music score to go along with it. That score will be blasted out on loudspeakers at Gas Works Park, and heard all over that area.

The lead pyrotechnician told us every boom is timed with a computer program to match the percussion and every note in the soundtrack.

Starting at 3 p.m. Tuesday, Gas Works will turn into a crowded summer festival-style atmosphere, with three beer gardens, family-friendly activities, and live music.

Last 4th of July, fireworks returned to Lake Union after it was dark for three years because of crowd restrictions during the pandemic.

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