The total loss of Lincoln Avenue Elementary School was triggered when Milwaukee Public Schools cleaning staff disposed of soaked cleaning rags in plastic garbage cans. Updates, she said, included mandating disposal of potentially flammable materials in metal containers, prohibiting the use of oil-based chemicals when temperatures exceed 85 degrees, providing metal garbage cans, mandating fire doors be closed at the end of a day and requiring employees to verify that a building is properly closed and secured at the end of a workday. The superintendent said an initial review identified that it would cost $1 million to $2 million per school to install a full sprinkler system, and the district has 139 buildings.