San Diego's fireworks are held actually inside the harbor, in the water for obvious reasons. They're set up on floating barges and can be seen from both the shoreline and all the land rising from the sea right up to the mountain mesas where the towns like National City and Chula Vista, Old Town, etc are located, which are all covered with homes in order to see the harbor and bay view toward the southwest. So all the fireworks this year, on the 4th of July were set up to go off in four series of explosions, each one after the previous set. This display was scheduled to start at 9:00 Pacific Time and should have run over a period of 20-30 minutes with a grand finale at the end.
HOWEVER. The computer literally running the show, somehow had a glitch. My cousin, who was sitting on his rooftop for a better perspective, had just sat down with his bowl of popcorn to watch the show. At TWO minutes BEFORE 9:00, he saw the whole horizon light up with one powerful BLAM, as all four barges sent a couple million dollars' worth of delightful explosives into the air over the San Diego Harbor. It took a grand total of 20 seconds.
I didn't see this display, which was over before it began, but I suspect it look quite a bit like the sky over Pearl Harbor in 1941.