Health officials upgraded three probable swine flu cases in the Deer Park school district to confirmed Monday as students began a health department-imposed break from school.

Swine flu fears caused officials to close all schools in the Deer Park Union Free School District for the entire week. The Suffolk County Health Department recommended the district close John F. Kennedy Intermediate School after three probable cases of swine flu were reported there. However, the district decided to close and sanitize all schools and buses in the district.

Officials say none of the three students who have the flu traveled to Mexico or have ties to St. Francis Preparatory School in New York City, where dozens were sickened by the virus. They are investigating how the students may have gotten infected.

A tentative reopening date of May 11 has been set.