(CNN) -- When most of the country was going ooh and aah over Fourth of July fireworks displays, San Diego spectators were treated to a spectacle that lit up the night sky -- for all of 15 seconds.

Thousands had gathered at beaches and parks to catch a glimpse of the annual "Big Bay Boom" show on Wednesday night. Some camped out for hours to see the fireworks that ignite around the San Diego Bay on Independence Day.

An unknown glitch caused the fireworks to explode all at once, botching the show and bewildering spectators.

Others fled into the night as four big balls lit up before their scheduled time, adding to the confusion.

The Big Bay Boom was a Big Bay bust.