2 major earthquakes show it'll take some tweaking to get Shake Alert app right

The two earthquakes many Angelenos felt over the Fourth of July weekend weren't just cause for the usual excitement, curiosity, or even fear last week. They also inspired anger.  Angelenos received no warning about the temblors from an alert app introduced earlier this year that was marketed as the country's first early warning system for earthquakes. That caused some to express frustration at the city and mayor on social media, even though officials say the app was working as it should. Althou...