An unusual bug on Facebook briefly labelled many people as dead.
The error on Friday caused the social network to show a memorial banner on user profiles for people who were still alive.
Users posted status updates to reassure friends and family they were not dead, despite Facebook's message.
"This was a terrible error that we have now fixed," a Facebook spokesperson said. "We are very sorry that this happened."
The message, intended for "memorialised profiles", erroneously appeared on the profile pages of a large number of users – including Facebook CEO Mark Zuckerberg.
Technology reporters and Facebook users, however, saw a humorous side to the story.
"Why Is Facebook Saying I'm Dead?" asked the New York Times' Katie Rogers. "At first, I was indignant. I was definitely not dead. Then I thought I had been hacked. Then I asked a few of my colleagues. Also dead."
"Facebook is capping one of the longest weeks in American history by telling everyone that they are dead," quipped The Verge, a technology website, in reference to the presidential election.
The memorial feature was introduced by Facebook in 2015 because of a number of high-profile cases where family wanted to access the social accounts of deceased loved ones.
User can opt to have their account turn into a memorial page upon their death, where Facebook contacts can leave message and share memories.
An alternative option is to have your account deleted after your death.