"...The tipping point becomes when school district closings are announced, forcing working parents to have at least one parent home during the day..."

A Seattle High School had 170 students out sick Mon, 200 yesterday, and 300 today, some so sick they are in the hospital. So the school has shut down for at least the rest of this week. So there are undoubtedly a lot of working parents scrambling to cover the rest of the week, and hopefully not get sick themselves...