The cause of the blaze has not been determined, but authorities said it appeared to be accidental, not arson or terrorism. The background note was posted by a system YouTube to combat well-known conspiracies about such events as the moon landing or 9/11. When YouTube announced its anti-conspiracy efforts last summer, it said it would counter bogus information with sources people generally trusted, such as Wikipedia and Encyclopedia Britannica. Videos of the Notre Dame fire were shown by large, trusted news organizations. On Monday, the company quickly fixed the Notre Dame error and said its systems sometimes make the wrong call.

Source: ABC News April 16, 2019 19:41 UTC