More than half the teachers at a Compton high school called in sick Tuesday, leaving students unattended and forcing district officials to scramble to bring order to the campus.
The Compton Unified School District blamed labor action for the absence of teachers at Dominguez High.
District spokesman Ron T. Suazo said 55 of 86 teachers called in sick Tuesday.
The lack of student supervision immediately disrupted the campus. Unable to proceed normally, "students remained at school until they were picked up by their parents," Suazo said.
Supt. Darin Brawley said the action violated the district's collective bargaining agreement with teachers.
"It appears teachers may be dissatisfied with the lack of progress related to negotiations," Brawley said in a statement.
"Regardless of the reason for today's event, students should never be used as pawns in conducting the business of the district. ... We intend to ensure there are no further disruptions."
Brawley also vowed to launch an investigation.
Attempts to contact union leaders were not successful.
A community member said he drove by the school in the morning and noticed students running around the campus. He said students told him about the absence of the teachers.