BURIEN, Wash. – Thousands of families in Burien suddenly needed to plan for child care Monday after Highline Public Schools canceled classes due to a possible cyberattack. The announcement was made by the district at 3:15 p.m. Sunday.In addition to closure of classes, school activities, athletics and meetings are canceled as well, including the vaccine clinic. There are more than17,500 students in Highline schools, according to its website.