In the middle of Saturday’s stormy evening, a massive, private fireworks show in San Francisco startled folks on both sides of the Bay.

Around 9:45 p.m., a fireworks show that lasted a little more than 10 minutes began from a barge in the San Francisco Bay. The Saturday night show was part of an annual celebration for Computers and Structures, Inc. (CSI), a software company for the building industry.

It’s the second year in a row that CSI’s post-party fireworks show caught people off guard. When last year’s show similarly rattled the region, the Port of San Francisco told ABC7 they would consider ways to increase transparency about future private fireworks. This year, the port sent out a notification via an email list about the planned show on Saturday, which at least one person posted about on Reddit ahead of time.

On Reddit, a commenter noted the timing of this show around the ongoing US-Iran tension and said they “really thought this was it for us” when the booms and lights began. Another Redditor, who said they were in the shower and only a block away from the show when it started, quipped that it was “maybe not the best geopolitical timing for surprise fireworks of this caliber.” 

Some who saw the show complimented the quality of the fireworks display, with one person on Threads saying it “rivaled the New Year’s Eve show they do for the whole city.” But the sheer size of the fireworks meant the booms were not just heard, but also felt in the East Bay. One person wrote, “I’m in North Oakland and it’s rumbling my whole apartment.” They also confused one Berkeley resident, who said, “I thought it was just a constant surge of thunder.”