One of 9 bridges crossing the LA River in Downtown LA, the Art Deco Sixth Street Viaduct constructed in 1932, has a terminal case of "concrete cancer" (alkali–silica reaction, or ASR) which leads to structural failure over time. Predictive models project a 70% probability of total failure during a major earthquake within 50 years. It's scheduled for demolition this summer (2015). Fortunately, the iconic bridge connecting Downtown Los Angeles' Arts District with Boyle Heights, is preserved in countless films and music videos. The swooping arches of the new cable stayed design, pays tribute to the original...