A new, loud noise blared in ocean beach during the dense fog. 10News reveals why some residents didn't recognize the sound.
"It was all day every day," said Kara Roach.
It went off, almost non-stop.
"I did think to myself, I've never heard this before," said Roach. She lives in Ocean Beach, just a couple blocks away from the pier.
She and other residents have noticed a new, blaring horn this weekend.
"I went to bed probably at like 1:30 a.m. and it was still going off," said Roach.
The culprit: a new fog horn.
The previous fog horn was decades old and broke last year, according to lifeguards.
He said it went off for several hours, every 15 seconds. It was only activated when the fog was extreme.
"It's designed to be loud enough that boaters far away can hear it so they don't come too close to the Ocean Beach pier."
Weather conditions can have an affect on sound.
"That's why the community of Ocean Beach often times will hear the fog horn better than off shore," said Lerum.
He said the horn will be activated again if they see fog rolling in. It's shut off as soon as conditions start clearing.