This is one in a weeklong series of stories on KPCC leading up to Friday's 20th anniversary of the devastating 1994 Northridge Earthquake. The series will explore the quake's history, its effects and its legacy. You can view more stories on our Northridge Anniversary page. Let us know what you think on our Facebook page, on Twitter ("@" mention @KPCC) and in the comments below.
When the Northridge earthquake struck 20 years ago, L.A. was a very different place.
The Internet was brand new. Cell phones looked like bricks, and if you said "Facebook" most people would think you were talking about an actual book.
These days though, digital technology is everywhere.
It helps us in many ways, but our reliance on connectivity may also end up hurting us after a major quake.
"Everything and anything that we use is dependent on some type of electronic or digital tool," said Julie Davenport, a disaster preparedness expert who spent decades creating emergency plans for Wells Fargo.
Davenport says it's possible for a major quake to take out much of L.A.'s communication infrastructure.
In such a scenario many point-of-sale systems that process debit and credit card payments wouldn't work. Gas pumps may be inoperable, and a quarter of all ATMs in the city could be offline.
Davenport suggests people keep a stash of cash at home and maintain a semi-full gas tank at all times.
U.S. Geological Survey seismologist Lucy Jones adds, many important public and private entities rely heavily on the web.
She says Caltrans uses the Internet to monitor roads and traffic conditions, electric and water companies use it to keep track of operations, and grocery stores need it to order food.
"We assume it is in just about every aspect of economic activity," she explained.
Related: KPCC's Earthquake Tracker app
Jones says two-thirds of L.A.'s connectivity comes to the area through fiber optic cable that cross the San Andreas — a fault that she says is overdue for a big quake.
"And when that happens, we know exactly where the fault is going to move, and it's going to move 20 or 30 feet, and everything crossing the fault will be offset," she said. "That will rip the fiber optic cables apart."
On top of that, many cell towers will likely suffer damage, and the cell network will clog with calls and data requests. This could be a problem since she says because some emergency responders have abandoned radio technology for cell phones.
Disaster preparedness expert Julie Davenport says many larger companies, like the bank she worked for, have back-up systems to rely on if local connectivity is lost.
But she says smaller businesses may not be able to function without a digital hook up.
This concerns Lucy Jones, who says catastrophes like Hurricane Katrina have shown that when too many businesses fail it can encourage people to leave a region for good.
She worries Southern California would share a similar fate if it were offline for more than a few days.
"If we lose it for longer than that — then we really are threatened with the economy falling apart in a way that it will take us many decades to recover," she said.
"Lighting up" L.A.
Technology to get L.A. back online quickly after a mega-quake does exist, says Brent Woodworth, president of the Los Angeles Emergency Preparedness Foundation, a nonprofit that helps prepare the city for various catastrophes.
He says a system called WiMax can beam Internet connectivity from satellites to receiver dishes on the ground. Those dishes can in turn cast out a net of Wi-Fi-like connectivity to entire neighborhoods.
Woodworth says the system costs several million dollars but could be vital after a major disaster, especially since many relief workers use digital maps and social media to coordinate efforts.
It's one of many plans his group is considering to improve L.A.'s chances of bouncing back after the next earthquake.
"I am very optimistic about what this city has done," Woodworth said, but he added, "There is still a long ways to go."
"Then and Now" Photo Gallery