Conversion to electricity was resisted by opponents like Rudolph Spreckels and other property owners who objected to what they saw as ugly overhead lines on the major thoroughfares of the city center. At 5:12 am on April 18, 1906, those objections were swept away as the great San Francisco earthquake struck. The race to rebuild the city allowed the company to replace all but the steepest of its cable car lines with electric streetcar lines.