Residents across Nevada and California were startled Thursday when their phones erupted with an earthquake alert warning of a powerful 5.9 magnitude.
The US Geological Survey (USGS) issued the warning just after 11am ET (8am local), triggering 'Drop, Cover, Hold On!' messages as far as 200 miles from the supposed epicenter near Carson City, Nevada.
A quake of that size can inflict moderate damage even on well-built structures.
But minutes later, the USGS abruptly wiped the event from its system.
'There was no M5.9 earthquake near Carson City, NV,' the agency said on X, adding that it was investigating why the alert went out at all.
MyShake, the app that forwards alerts from the USGS ShakeAlert system, confirmed it had relayed a false alarm.
The erroneous warning reached cities as far west as San Francisco, 185 miles from the reported location, leaving residents confused and shaken.
'Phones blasting alerts across Nevada and California to 'Drop, Cover, Hold On!' Aftershocks coming,' one user wrote online.
California Governor's Office of Emergency Services confirmed on their X account that false alerts were sent out 'to a broad audience in Northern California.'
'Cal OES is coordinating with our Nevada and federal partners to understand exactly what the federally run monitoring system detected and why,' the agency added.
'No earthquake false alarm! Someone got trigger-happy after all the earthquake talk,' another social media user posted on
USGS released a statement responding to the criticism from Cal OES, saying that the agency would 'provide more information when we learn more.'
The MyShake app called the false alarm 'unprecedented and rare,' adding that their alert system had provided over 170 accurate alerts since 2019.
The MyShake app sends out a buzzing alert to all of its users for earthquakes stronger than magnitude 4.5.
Yaareb Al Taweel, a geophysicist with USGS, told the San Francisco Chronicle: 'If you sign up to receive those messages, it doesn't matter where you're at, you will receive this message on your email or phone.'
While the mistaken notification may have been unprecedented for MyShake, it wasn't the first significant false alarm to panic Californians this year.
On March 14, USGS erroneously posted on its website that a magnitude 4.6 earthquake had been detected near Bombay Beach in San Diego.
Just as they did with Thursday's alert, USGS deleted the March 14 post from its live map about two hours later.
Northern California, where a large number of Americans received the false alert, has been warned that there is an extremely high chance of a major earthquake striking the region within the next 30 years.
Sarah Minson from USGS revealed in May that the chances of the long-feared 'Big One' striking San Francisco by 2055 have risen to a staggering 72 percent.
While Minson believed there may be some time left for Californians to prepare for this natural disaster, USGS disagreed and warned on its website that the first major earthquake could come in just seven years.
A magnitude 5.9 earthquake would have been considered by seismic officials as an extremely 'moderate' quake and potentially a 'strong' quake if it reached magnitude 6.0.
However, quakes of this size would have been felt all the way in the Bay Area, 200 miles away, and would have caused cracks in walls, some building collapses, broken windows, and several injuries in the areas closest to the epicenter.
