California's earthquake warning system on shaky ground

EAGLE ROCK, LOS ANGELES (KABC) -- When Tuesday's devastating earthquake struck Mexico, people there actually knew it was coming.

PHOTOS: Powerful earthquake hits central Mexico

A national earthquake warning system provided a 20-second heads up. But here in the United States, no such national warning system exists, just a California-based pilot program called ShakeAlert.

MORE: Important items you should have in your earthquake kit

The U.S. Geological Survey's early earthquake warning system was first put into use in 2012, but it still considered a prototype.

Its warnings go out to California emergency centers, some private businesses that are test users, as well as Eagle Rock High School, which signed on as a trial member nearly two years ago.

MORE: Mexico earthquake's shaking worse because of soil conditions, seismologists say

"To have those precious seconds to be able to prepare and get away from danger are invaluable," said Eagle Rock science teacher Ali Kobassi

But ShakeAlert's future is murky. Earlier this year, the Trump administration proposed completely wiping out the ShakeAlert budget.

Congress has been able to block those cuts, but ShakeAlert's next round of funding has yet to be determined.