These days, Chris Bowers wakes up every morning to a vivid reminder that crossing borders can get you killed in South LA's Harbor Gateway area. Just outside the fence in front of his rented stucco house on Harvard Boulevard is a silver scooter, an assortment of dried flowers and a dozen candles bearing religious messages written in Spanish and English--a makeshift memorial to Cheryl Green, the 14-year-old whose murder last December by members of the 204th Street Gang sparked accusations of Latino "ethnic cleansing" of African-Americans.

"There's no vision or larger plan about where to put high-density corridors, or what is going to be the impact of this density on traffic," said Anastasia Loukaitou-Sideris, chairwoman of UCLA's urban planning department. Steven P. Erie, director of the Urban Studies Program at UC San Diego, said the city's projections for sewer, transportation, public safety and other needs would have to change to accommodate the crush of people in a small area that would result from the construction of very high condominium or apartment towers.