THURSDAY, Feb. 21, 2019 (HealthDay News) -- First came confusion, shock and fear, as people struggled to process the emergency warning they'd received.
"There's a missile threat here right now guys. I love you all and I'm scared as [expletive deleted]."
Later came anger, mistrust and denunciation, when they found the frightening warning had been false.
"And now, should there be another ballistic missile threat, how can we trust it knowing the last one was a grave mistake???"
Tens of thousands of Twitter messages provide a real-time window into the public reaction to a 2018 errant alert warning Hawaiians that a ballistic missile had been fired at their island state, according to a new study from the U.S. Centers for Disease Control and Prevention.
The reactions show the powerful effect a government warning can have on citizens, and the loss of credibility that can happen if someone has cried wolf.
But on a more positive note, the messages also display the power of social media to help inform people during a crisis, said lead researcher Dr. Bhavini Patel Murthy, a CDC medical epidemiologist.
"People on social media did turn to government organizations, as well as news media, to try to find out what was going on and how they should react," Murthy said. "Given that social media has transformed the way individuals consume and share information, that is how we can effectively communicate to the public, whether it's to a certain area or nationwide."
The false alert came at 8:07 a.m. on Jan. 13, 2018, in Hawaii, the result of a state Emergency Management Agency employee mistaking a training drill for an actual threat, researchers said.
The alert said there was a ballistic missile headed toward Hawaii: "Seek immediate shelter. This is not a drill." It ran over television and radio, and even popped up on people's cellphones.
Escalating tensions between North Korea and United States lent the alert plausibility. North Korea had conducted several ballistic missile tests during the previous year, raising concerns that Hawaii could be the target of a nuclear attack.
It took state officials 38 minutes to retract the alert. Investigations subsequently led to the resignation of the state's emergency management administrator.
As the event unfolded, tens of thousands of people took to Twitter to share information and learn more about the crisis, Murthy and her colleagues found.
Analysis revealed that 127,125 tweets were sent out in the 38 minutes following the alert and the 38 minutes after it had been retracted, researchers reported in the Feb. 22 issue of the CDC's Morbidity and Mortality Weekly Report.
The researchers boiled all those messages down to 14,530 initial tweets, excluding retweets and quote tweets.
They found that four themes emerged in the tweets sent while the threat was believed to be real:
After the alert was rescinded, people continued to use Twitter to share information and express their emotions regarding the false alarm, researchers said.
But three new themes also emerged in the minutes after people learned they'd been warned for nothing:
Still, all these tweets highlight the opportunity that social media provides for public health and emergency response officials to communicate with citizens during a crisis, Murthy said.
"Public health practitioners should consider how people interpret, share and react to public health messaging as a situation unfolds, and how we can meet people where they are to convey timely information," Murthy said.
Tamer Hadi directs strategic technology for the New York City Department of Health and Mental Hygiene's Office of Emergency Preparedness and Response. She said the study shows that "public health agencies must use social media bidirectionally -- as in, using social media for both outgoing risk communication as well as incoming feedback from the public and media."
Officials should stay on top of social media during a crisis, said Hadi, a member in the Public Health Communications Committee of the National Association of County and City Health Officials. He was not involved with the CDC study.
"Upon picking up on trends of questions, concerns or misinformation by both the general public and the news media, health departments should use that information to revise and repeat key points to ensure clarity and understanding," Hadi said.
Timely communication is also key.
"It is critical that public health agencies release communication on social media as quickly as possible after an incident," Hadi said.
"It is important to acknowledge both what is known and unknown, and follow up consistently from that point on. The longer time that passes without official information, the more time there will be for misinformation and rumors to be exchanged," he noted.
Ventura County, Calif., has more about preparation and response to a nuclear explosion.