LOS ANGELES (CBSLA) — The City of Los Angeles announced they would lower the threshold on the current Shake Alert L.A. App following a magnitude 6.4 earthquake rattled the city.

Residents across the southland were concerned when they did not receive a Shake Alert for the powerful earthquake that struck Ridgecrest Thursday.

USGS Shake Alert put out a tweet clarifying why Los Angeles residents were not alerted on their app saying, “The @LACity #ShakeAlertLA app sends USGS ShakeAlerts to people in @CountyofLA at M5.0+ for areas that could experience potentially damaging shaking.”

The City of Los Angeles explained that the app only alerts when the shaking is over M5.0 in L.A. County, and the shaking in L.A. on Thursday registered at M4.5.

Following the quake, the City of Los Angeles announced they would be lowering the alert threshold with the USGS Shake Alert.

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