Radio Caroline in Essex accidentally announced the death of Britain's King Charles III live on air – the cause was a computer glitch.
The Guardian writes about this.
“Due to a computer error in our main studio on Tuesday afternoon (May 19), the 'Death of the Monarch' protocol, which all British radio stations keep on standby, hoping never to have to use it, was accidentally activated. As a result, the announcement that His Majesty the King has died was mistakenly broadcast,” the station's manager, Peter Moore, wrote on Facebook, apologizing “for any distress this may have caused.”
The post does not specify how long it took for the error to be noticed, but the incident occurred while King Charles and Queen Camilla were in Northern Ireland.