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:
The_Blitz

Context:
Much civil-defence preparation in the form of shelters was left in the hands of local authorities, and many areas such as Birmingham, Coventry, Belfast and the East End of London did not have enough shelters. The Phoney War, however, and the unexpected delay of civilian bombing permitted the shelter programme to finish in June 1940.:35 The programme favoured backyard Anderson shelters and small brick surface shelters; many of the latter were soon abandoned in 1940 as unsafe. In addition, authorities expected that the raids would be brief and during the day. Few predicted that attacks by night would force Londoners to sleep in shelters.

Question:
What civil-defense efforts were left to local authorities to handle?

shelters