LOS ANGELES (AP) — The tallest building west of the Mississippi River opened its doors Friday, celebrating with lights and fanfare in once-stodgy downtown Los Angeles that is sprouting a crop of new skyscrapers. Here are some things to know about the Wilshire Grand Center: HOW TALL IS TALL? The 73-story building has a huge spire that brings its height to 1,100 feet, topping the nearby U.S.