The three-day strike that shut down public schools in Los Angeles may have been illegal, according to complaints issued by state regulators, clearing the way for the district’s case against the two unions that walked out to move to a formal hearing.

The actions by the California Public Employment Relations Board do not represent a determination that the unions acted illegally. Instead regulators concluded that the Los Angeles Unified School District made a strong enough case to move to the next stage in the legal process.

The strike took place March 21-23. The labor board issued a complaint against one participating union on March 21 and the other on March 22, but neither the school district nor the unions announced the regulatory action at the time. Click here to read more: