It seems that the town doesn't have the patience for poor education.
In spite of the fact that the average income for teachers in that district is more than 3 times the average of Central Falls residents ($70-78K vs $22K), apparently working an extra 25 minutes per day to tutor students in the woefully underperforming school was to much for them.
When the teacher's union rejected this burdensome demand, the town fired them all.
From Strzok to Contreras
24 minutes ago