Coast Guard officials said it appeared that entire battery of explosives on three of the four launch barges was launched at the same time, possibly due to a "premature ignition."
"It looked like the finale ... you know, right at the end they shoot off everything." said Rich Dann, a civilian Coast Guard employee at the San Diego station.
Port officials said on the agency's Twitter page that they "sincerely apologize for the technical glitch that affected Big Bay Boom. Event producers are currently investigating the cause."
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