Elsa Devienne takes us behind the iconic beaches of Los Angeles to reveal a hidden history of transformation, conflict, and reinvention. The author of “Sand Rush,” Devienne discusses how L.A.’s shores went from eroding, polluted strips in the 1920s and ’30s to expansive public spaces that defined the city’s image and culture. She details the social and political forces that played out, from the exclusion of minority communities to today’s ongoing battles over coastal access. With echoes of “Chinatown” and insights into today’s wealth-driven coastal fights, Devienne’s work helps illuminate Los Angeles’ evolving identity.