SAN DIEGO (KGTV) -- San Diegans are scratching their heads after a puzzling boom swept through the county Wednesday afternoon.
Residents all over the county reported the incident around 5 p.m. from Escondido, to 4S Ranch, University City, and Pacific Beach.
Some described the noise as a bang while others described a rumble. "Heard it in Chula Vista and windows rattled," one Facebook commenter wrote.
"It was a loud boom and windows shook like they were going to blow out," another said.
At this time the United States Geological Survey hasn’t reported any earthquakes in Southern California.
Officials with Camp Pendleton confirmed that the base is performing artillery training Wednesday but couldn’t confirm whether or not the exercises were responsible for the boom.
This is the second time in 2021 an unexplained boom was reported. The first happened February 16.
10News will continue to keep you updated as soon as we receive more information.