Relentless rains pounded the Los Angeles area for hours Sunday as a storm passed from the Pacific Ocean into Southern California, flooding streets and highways and sending a section of a coastline street into the sea. A chunk of coastal bluff that had been creeping toward the ocean for months gave way and part of the street that sat on it buckled and crumbled into the Pacific amid hard afternoon rains, Mayor Antonio Villaraigosa said in a statement.