Original: 1978 & ndash ; Following the murder of Mayor George Moscone , Dianne Feinstein becomes San Francisco , California 's first female mayor ( she served until January 8 , 1988 ) .
Simplified: 1952 - Great Smog of 1952 : A cold fog descends upon London , combining with air pollution and killing up to 12,000 in the weeks and months that follow .