BROOKLYN - Work on more than 2,000 affordable housing units promised as part of the Atlantic Yards project has yet to begin, according to a published report. The Wall Street Journal reports that Forest City Ratner has yet to break ground on more than 6,000 housing units, 2,000 of which are supposed to be affordable housing. The company once projected the housing units to be complete by 2016, but the Wall Street Journal says higher-than-expected costs have caused delays. Still, CEO Bruce Ratner says the company plans to break ground later this year. If Forest City Ratner doesn't begin the project by May 2013, it must pay the city $5 million.