An undercover investigation by the Government Accountability Office lowers the boom on the Department of Labor for failing to protect workers. The GAO's findings -- released at a congressional hearing Thursday -- show that the labor department's Wage and Hour Division failed to respond not just to mundane complaints about missing paychecks and overtime pay, but even a tip that school-age children were operating dangerous machinery during the school day. Ten GAO operatives called the department to complain of missing paychecks, unpaid overtime, and below-minimum wages.