Construction of the Metro Gold Line Foothill Extension bridge, that will span the 210 Freeway, has begun. Preparation of the giant column supports included drilling over 100 feet into the ground. The 584-foot Gold Line bridge will take shape by December. It replaces an old railroad bridge across the freeway, which was built about 1969 and torn down in 1997, said Gary Baker, director of construction for the Metro Gold Line Foothill Extension Construction Authority. The bridge's design has been controversial, as some say it is not representative of the origins of the area. The entire bridge is slated to be finished summer 2012.