Trunion Bascule Bridge aka Ford Ave. Bridge, May 13, 1930 - Alleged to have been (at that time) the World's largest Bascule Bridge.

http://skyscraperpage.com/forum/showpost.php?p=6058792&postcount=13402

the building seen under the bridge is the Long Beach Ford Manufacturing plant (thanks David!)

http://www.fordmotorhistory.com/factories/long_beach/photos_9.php