You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Doctor_Who

Context:
It has been claimed that the transmission of the first episode was delayed by ten minutes due to extended news coverage of the assassination of US President John F. Kennedy the previous day; whereas in fact it went out after a delay of eighty seconds. The BBC believed that many viewers had missed this introduction to a new series due to the coverage of the assassination, as well as a series of power blackouts across the country, and they broadcast it again on 30 November 1963, just before episode two.

Question:
What other event made the BBC concerned that viewers had not seen the premier of Doctor Who?

a series of power blackouts across the country