LOS ANGELES - What if there was a way for you to know that a quake is coming?
"It said it was a 5.4 and I could see that it was centered near the Channel Islands," said Alissa Walker, an editor at Curbed Urbanism.
Alissa Walker knew all thanks to an app on her phone called "QuakeAlert."
"I got a warning, it said I was going to feel it, and I did feel it," Walker said.
Walker has been writing about early warning systems for years for Curbed Urbanism. So last year when she wrote a story about this app, the creators gave her beta access to test it out. She showed us how it worked.
"The first thing that happens is you get an alert sound on your phone and you look down and it said on my phone 38 seconds until expecting weak shaking," Walker said.
She also got this map - which showed her not only where the epicenter is - but also how far it is from her location and the magnitude.
Josh Bashioum/Early Warning Labs Founder: 00:34 "Scary day for some, but for us it was a good day," said Josh Bashioum, a founder of Early Warnings Labs.
Josh Bashioum is the founder of Early Warning Labs, the company that developed the early warning software which is now being rolled out all over Southern California and right here in Los Angeles.
"We notify Metro and they'll actually slow and stop all of their trains and they can do that in about half a minute...and if we can do that, we can prevent derailment," Bashioum said.
Bashioum says the early warning system not only told people how much time they had before it arrived, it also let them know it was going to be a weak earthquake so they knew not to panic. Alissa Walker experienced that first hand.
"If it had said strong shaking or moderate shaking, I would've definitely tried to get under my desk in that amount of time because you just don't know," Walker said.
Seismologist Dr. Lucy Jones says the warning system will provide precious seconds.
"What it does is it allows a surgeon to pull the knife out of your chest, the dentist to take the drill out of your mouth, the elevator to move to the nearest floor and open the door so when the electricity goes out on a really big earthquake, you aren't stuck there for the next three days," Jones said.