By CBSLA Staff

LOS ANGELES (CBSLA) – If the big one hits people may be left without cell service – for weeks. That’s what the latest earthquake research shows and the damage in Southern California could be almost impossible to comprehend.

Thursday was the “Great ShakeOut Day” when emergency coordinators encourage the public to prepare for the inevitable “big one” in California.

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Today, new research was unveiled giving the public a sobering look at what life could look like after the “big one” on the San Andreas fault.

New United States Geological Survey (U.S.G.S.) projections reveals that if a big one hit in the bay area – like the 1989 Loma Prieta earthquake – then 93 percent of all cell phones would fail – possibly for weeks.

(Photo by Will Lester/MediaNews Group/Inland Valley Daily Bulletin via Getty Images)

“Most cell towers in California have four hours of backup power,” said Dr. Lucy Jones, a seismologist. “If we lose electricity for longer than that we’re going to lose our ability to even text.”

The loss could cripple 911 systems – making it impossible to connect with family.

“The system is going to overload. Sometimes you can’t get a call through when in rush hour, you’re not going to get a call through,” said Dr. Jones. “But texting takes much less bandwidth. So many, many more texts can go through where the phone call can’t.”

A virtual town hall was held at the California Institute of Technology on Thursday with the latest models on what the the “big one” in Southern California would look like with a 7.8 magnitude with the epicenter in the Coachella valley along the San Andreas.

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The animation showcased terrifying progression, heavy energy and intense shaking, sweeping up from the San Gabriel Valley and LA Basin. The shaking went on nonstop for up to two minutes.

“A 7.8 on the San Andreas, that’s the Shake Out scenario that started the drill, and our modeling was 1,800 dead – with half of them killed in fires,” said Dr. Jones.

(Photo by Brittany Murray/MediaNews Group/Long Beach Press-Telegram via Getty Images)

The latest models show a quarter-million people displaced, 300,000 buildings heavily damaged, 50,000 injured and 1,800 dead.

The model show half of all deaths would be in fires. Firefighters may not be able to enter heavily damaged neighborhoods, water mains broken in northern Orange County, and the LA basin, home to tens of thousands of densely packed wood frame buildings, hundreds of square blocks would burn.

“A 7 or 7.5 [magnitude earthquake] in Puente Hills, or Hollywood or Santa Monica – or Newport Inglewood Fault. Those have the potential to have many thousands of dead,” said Dr. Jones.

Dr. Jones does emphasize our state has been preparing for the big one for some time.

“California has focused on life safety. That’s our big thing about earthquakes – you can’t kill somebody. You can be a complete financial loss, that’s your choice – but you can’t kill someone in the process,” said Dr. Jones. “Our buildings do a very good job of not collapsing. Our big risks are from old buildings that are not up to the current standards.”

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The latest models show that after a 7.8 magnitude earthquake, it’s possible there could be aftershocks for decades, with many over 6.0 magnitude.