CHICAGO -- Crowds of over 100,000 people crammed Navy Pier to celebrate the Fourth of July firework show.
The parking lots were filled by 6 p.m. and Navy Pier was filled to capacity by 8 p.m., Navy Pier officials said.
Crowds came early to claim prime viewing real estate for Saturday night's dazzling fireworks extravaganza.
Officials said their security plan included uniformed and plain-clothes police officers. Workers also checked bags at the entrance.
However, someone managed to sneak an M-80 firework through the gates and set it off near the IMAX theater.
It caused a scare because some people thought they were hearing gunfire.
No one was injured and no damage was reported.