Radio Caroline, a former British pirate radio station, apologized on Wednesday after accidentally announcing the death of King Charles III the previous day.

A computer error at the station’s main studio in Maldon, eastern Essex, triggered the erroneous announcement on Tuesday afternoon. The mishap came as Charles and Queen Camilla were in Northern Ireland, where they joined a performance with an Irish folk group.

How did Radio Caroline accidentally announce the death of King Charles?

The computer error activated the station’s so-called death of a monarch procedure, a protocol that all UK stations hold in readiness.

The station then fell silent, as the procedure requires, which alerted staff to restore programming and issue an on-air apology. Station manager Peter Moore confirmed the sequence of events in a post on Facebook.

What did Radio Caroline say in its apology?

Moore wrote that the station had been “pleased to broadcast Her Majesty the Queen’s and now the King’s Christmas message” and hoped to continue doing so for many years. “We apologize to HM the King and to our listeners for any distress caused,” he added.

The post did not specify how long it took before the mistake was discovered, but the domestic Press Association reported that on Wednesday afternoon, playback of Tuesday’s broadcast between 1:58pm and 5:00pm was unavailable on the station’s website.

What is Radio Caroline and why does it matter?

Radio Caroline was established in 1964 to challenge the BBC’s broadcasting monopoly, operating from ships off the English coast.

Legislation in 1967 forced many pirate broadcasters to close, but the station continued intermittently before ending offshore broadcasts in 1990.

Caroline and similar pirate stations inspired the 2009 comedy film “The Boat That Rocked,” starring Bill Nighy and Philip Seymour Hoffman, about a group of eccentric DJs living and working together at sea.