The Superior Fire Department has released a rough timeline of the fires that caused an estimated $1.5 million to the new Cooper Elementary School, under construction beside the current school building at 1807 Missouri Ave. Arson is not suspected, although the cause of the fire has yet to be determined. Fire inspectors suspect the original fire Sunday night started in the gymnasium storage area, burned through a one-inch flexible rubber natural gas line and went out. Gas flowing from the boiler room reached the heat from the original fire, firefighters reported, causing an explosion, a process that was repeated multiple times.