Harvard Maintenance Inc., a national janitorial company, will lose over half its Minnesota work force after an immigration audit, making it the second major business in that state to be hit by an Obama administration crackdown on employers of illegal immigrants. The audit by U.S. Immigration and Customs Enforcement will result in about 240 workers losing their jobs, the Service Employees International Union said on Monday. J. Daniel Duffy, an executive vice president of the closely held New York-based janitorial company, declined to comment. Harvard Maintenance began issuing dismissal letters to employees in early March and is in the process...