Three public elementary schools in Warwick, Rhode Island, were closed on Monday.
Secretary to the Superintendent of the Schools, Catherine Bonang told WJAR-TV that the number of faculty absences has risen to a level in which the staff cannot safely open the schools.
"This decision was based on staff requirements, student needs and programs in the buildings," Bonang said in a statement.
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The schools that will be closed are Oakland Beach Elementary School, Park Elementary School, and E.G. Robertson School.
School officials told WJAR-TV that teacher sick calls closed Pilgrim High School Oct. 6 and Warwick Veterans Junior Hig Oct. 11.
The teachers' union says previous sick calls were due to flu season and stress, but superintendent Philip Thornton told WJAR-TV that the calls were a labor action.
Teachers have been working without a contract since 2015.