An algorithmic error told Californians they’d be in for a major earthquake on Wednesday, but the earthquake had already happened ”• in 1925.

The automatically generated report from the U.S. Geological Survey indicated that a magnitude 6.8 quake would occur in the Pacific Ocean 10 miles west of Santa Barbara.

 

Alerts were sent for a M6.8 in California. This was an error. More information to come.

— USGS (@USGS) June 22, 2017

As a frame of reference, a magnitude 6.9 earthquake in 1989 killed 63 people and caused $6 billion of damage in California.

So what gives with this quake scare?

 

Regarding: https://t.co/z8Ykmo6OXX pic.twitter.com/68Q0I2Ix2j

— USGS (@USGS) June 22, 2017

“The quake did happen, but it happened in 1925,” Rafael Abreu, a geophysicist with the U.S. Geological Survey, told The Associated Press.

This should seem like good news, but the false alarm still sent shockwaves through social media. Many automated tweets, synced with the USGS alert system, were pushed out, sparking concern.

Additionally, people around the country began to scratch their heads as no one had reported feeling tremors ”• something that most certainly would have happened in large numbers had an earthquake of that size actually come about.

Still, publications like the Los Angeles Times, which has automated emails from the USGS to aid in its coverage, ended up alerting the public about the fake quake and then had to rescind the messages.

@DrLucyJones M6.8 90 miles away Im sure we'd feel it right? Is this real? pic.twitter.com/OX1MzcgFrC

— Alex S (@alxxdes) June 22, 2017

The LA Times bot even generated an article about the fake quake:

Was the article automated too? pic.twitter.com/C8lMJa2dM9

— Colin Cooley (@runwicked) June 22, 2017

So, how did the USGS casually send out an alert that confused even the LA Times?

Apparently false alarms are fairly common, though the AP says “they rarely report quakes so big or in such populated areas.”

Also, researchers from the California Institute of Technology were using new information to analyze the epicenter of the 1925 earthquake in the Santa Barbara Channel. That earthquake ”• a real one ”• leveled several buildings and killed many people. You can see the LA Times’ article from that quake below:

 

False alarm: Caltech staffer accidentally sends alert for large 1925 Santa Barbara earthquake https://t.co/zSyy4Yzmvt pic.twitter.com/oNXJRUwZFN

— Los Angeles Times (@latimes) June 22, 2017

Even more intriguingly, the full quake report associated with Wednesday’s tweet listed the date as June 29, the same date as the 1925 quake, but indicated it would happen in the year 2025. So, yeah, that USGS report was all sorts of screwed up.

Let’s just hope they were wrong about any quakes in 2025 too.