This is the dome of San Francisco's City Hall during a dark Winter day.  Construction began on this edifice after the old, domed, City Hall, residing on the same location, was destroyed during the earthquake of 1906.  Some damage to the present building was incurred during the Loma Prieta earthquake of 1989.  Substantial seismic retrofitting has been carried out since the 1989 event.  Will it will survive the mother of all earthquakes -- which could strike at any moment?  Time will tell.  A City Birds photo.