Southern California residents woke up to an alarming emergency push alert on their phones Saturday morning, warning residents of Chevy Chase Canyon in Glendale to evacuate their homes.
But according to the city of Glendale, the "emergency" is actually just a drill.
"Public Safety Alert," the message read. "Chevy Chase canyon residents safely evacuate your home and proceed to the evacuation site located at the Glendale Community College Parking Lot B."
While the push alert itself did not elaborate, the City of Glendale did on social media.
"THIS IS A DRILL: #MyGlendale is conducting an evacuation exercise in Chevy Chase Canyon," the City's statement on Twitter read. "For those who live in Chevy Chase Canyon: Safely evacuate your home and proceed to the evacuation site located at the Glendale Community College Parking Lot B."
The "Public Safety Alert" made no mention of the fact the evacuation was a drill, causing alarm for residents who received it at 9 a.m. Saturday.
The alert was also issued to phones far away from Chevy Chase Canyon, with individuals as far as Santa Fe Springs, Hawthorne, Brentwood and Northridge taking to Twitter to express their confusion.
"I'm in Northridge," said one Twitter user. "I didn't even know where Chevy Chase Canyon was."
"Did this just go out to all LA County?" asked another.
The City of Glendale did provide warning on its official Twitter account ahead of time, issuing a statement roughly 20 minutes before the drill began.
The Glendale Fire Department also issued an advanced warning on Wednesday, telling residents of the drill on Saturday and providing a link to a short video explanation.
However, the advanced warning from the City of Glendale did not appear to be widespread outside of Twitter.
Roughly 30 minutes later, at 9:32 a.m. on Saturday, another push alert went out through the emergency system, stating the error.
"Disregard evacuation message for Chevy Chase Canyon," the second push alert read. "Training exercise only."
The same update was added to the city's Twitter account.
"There was an error in the tech used to send out this mornings message," the city said on Twitter. "We are working to remedy this issue. Updates to follow."
Silvio Lanzas, Fire Chief for the City of Glendale, explained to NBC4 that there were two parts to the tech error.
The first part, and the reason the alert went to most of LA County, was part of the emergency software's mapping system.
According to the fire chief, the Glendale Fire Department worked with the Glendale Police Department to send the alert for their sanctioned drill. According to the chief, the emergency software they use maps the area impacted by an incident that might need a warning.
The first responders preparing for the drill drew a map around the area that was supposed to receive the alert as part of the drill, and "...we put specific areas within that polygon in the map to identify just the Chevy Chase Canyon," Lanzas explained to NBC4.
"From what our early indications are that when you put more than 100 of those turns in the map, it defaults to a countywide message."
In other words, the software took a map designed to target around 5,000 Glendale residents, and decided that it was a dangerous enough "emergency" area that it automatically forwarded the message to all of LA County.
On Saturday, the area mapped for the drill was large enough that it triggered that automatic function -- sending the "public safety alert" to residents far beyond Glendale.
The other concerning error, the fact that the emergency alert did not note that the incident was just a drill, was due to a problem with the software that affected the heading of the push alert, according to the chief.
That heading was supposed to have either "exercise" or "drill" included, the chief said.
But either due to computer or human error -- it's not yet clear which -- that part of the heading never got included.
"The message was supposed to say, and did say on the header; ‘This is a drill’. That was scraped, we don’t know why yet, we’re looking into that," Lanzas said. "The header which I have seen personally said ‘this is a drill’. Again, we will learn from that."
Around 10:30 a.m., the city issued an official statement explaining the error.
"On Saturday, May 14, 2022, at 9:00 am, the City of Glendale conducted a planned evacuation exercise in coordination with the Chevy Chase Canyon Association," the statement reads. "Due to a glitch in the messaging software, incorrect messaging was distributed throughout Los Angeles County. The City is working with our partners to investigate."
The statement also reiterated the importance of such emergency drills, despite the error with this one.
In that statement, Lanzas "apologized to anyone negatively affected by today’s message."
"As we saw last week in Laguna Niguel, our fire environment in Southern California is prime for another potentially active Fire Season. Ensuring the community is prepared is key to keeping our residents safe," Lanzas said.
The emergency alert error came just days after a large fire in a Laguna Niguel neighborhood destroyed 20 homes and damaged 11 more, and just hours after brush fires near the 118 Freeway in Granada Hills burned for several hours.