It’s hard to pin down where, exactly, a conspiracy theory starts. It derives power from being seemingly everywhere at once, simultaneously unprovable and unimpeachable. But what we know about the Tiffany Dover conspiracy theory is this: Someone deceptively edited the video of her vaccination to make it look like she had died, leaving out the footage of her post-recovery interview. The video circulated on anti-vaxx Facebook pages and other social media accounts, accruing enough critical mass that by the time people got the facts, they weren’t interested in them at all. They were convinced a nurse had died, and they were going to get to the bottom of it.

In the days following the broadcast, commenters from around the world flooded CHI Memorial’s social media pages and even called the hospital, demanding proof that Dover was alive. Others sought out her friends and family, posting on their walls and Instagram pages demanding information. As evidence, they circulated screenshots of what they said was Dover’s death report on SearchQuarry.com—a website that will give an identical, similarly morbid result to anyone who enters their name.

By Dec. 19, the uproar was so intense that the hospital was forced to issue a tweet saying that Dover was “home and doing well” and asking for privacy for the nurse and her family. That tweet, too, was flooded with comments. “Send a picture of her with a newspaper of the day,” one wrote. “I want to see a video of her talking about it,” said another. (This according to screenshots taken at the time; the hospital’s account has since been made private.)