They've dubbed their push The Fight for $15 campaign after their aim of winning $15 an hour for workers.
Officials said they expected the death toll to rise.
Union leaders have strongly supported comprehensive immigration reform, including a path to eventual legalization and citizenship for 11 million undocumented people.
The president of Mexico's National Union of Miners, Metalworkers and Steelworkers, known as Los Mineros, reveals the government and business rot in detail.
Positions of authority, millions of dollars of personal wealth, slick public relations consultants, $1,000 per hour lawyers, privilege, and power cannot conceal the true purpose of this bankruptcy.
When fire broke out the supervisors told the female employees to return to work but smoke soon filled the factory.
The Steelworkers, the Autoworkers and the AFL-CIO formally oppose letting Japan join talks on the latest controversial "free trade" treaty, the Trans-Pacific Partnership.
The musicians, members of the American Federation of Musicians Local 6, overcame draconian proposals to slash pay of substitutes and extras.
Over labor and Democratic opposition, the GOP-run House has narrowly approved legislation (HR1120) to try to shut down the National Labor Relations Board.
Police managed to peacefully disperse the massive crowd. Firefighters responded to the alarms with trucks, ambulances, EMTs, and specially trained union members.