A 5.5 magnitude earthquake rocked Baja California, Mexico, on Friday night, and was felt as far as San Diego County. San Diegans have had a lot on their mind this past week, from the Covid-19 outbreak to now worrying about when the big earthquake will strike.

For decades, conventional thinking has always been San Diego County has a lower probability of devastating earthquakes than Los Angeles or San Francisco areas.

But a new report by the San Diego chapter of the Earthquake Engineering Research Institute (EERI), found a fault that runs through the heart of San Diego could be a much more serious problem than previously thought, reported Log Angeles Times.

EERI modeled for a 6.9 magnitude earthquake along the Rose Canyon Fault that runs directly through San Diego. What they noticed is that it would have devastating effects on local infrastructures, such as ruptured gas, water, electric, and fiber services between La Jolla and the Silver Strand, cause severe structural damage to tall buildings and lead to the destruction of major bridges across the county.

"We're expecting a large fault rupture, almost six feet, a lot of liquefaction impacts, which basically is softening of the soil that causes a lot of impact to underground infrastructure like water distribution pipes," said Heidi Tremayne, executive director of the EERI. "We're worried that coastal communities could really be lacking some basic services for many months after an earthquake of this magnitude."

With an 18% chance that Rose Canyon Fault could trigger a big quake in the next three decades, EERI said damage from it would cost upwards of $38 billion and account for $5.2 billion in lost income for local businesses.

"In the short term, I would consider getting a group of regional experts together and take a look at these recommendations and determine maybe a way ahead and mitigate some of these things so we're better prepared if in fact we have an earthquake along this fault," said Gary Johnston, the chief resilience officer for the San Diego County Office of Emergency Services.

There's without any doubt that California as a whole is long overdue for a destructive earthquake. We noted back in December that "very unusual seismic activity" was taking place off the West Coast.

Seismologists warned about a year ago that California's seismic activity is in an "earthquake drought." With fears of large quakes could be nearing.