The announcement came at a downtown rally involving three key unions that brought out thousands of participants. Los Angeles Unified's two largest labor groups -- the teachers union and service employees -- announced Wednesday they will join forces and both go on strike April 14 if no contract deal is reached before then, actions that would effectively shut down schools in less than a month.

The union representing workers at the JBS meatpacking plant in Greeley gave a required seven-day notice that it is cancelling its contract extension, effective midnight Sunday, March 15.