VIDEO: Fire crews in Alma are still working to determine what caused an explosion at a mill that led to a large fire. It happened at Dairyland Power Cooperative in Alma late Saturday night. The Alma fire chief says six departments were sent to the John P. Madgett Station in Alma. The fire ranged from the fourth to the sixth floor of the building. Several area fire departments were on scene last night. No one was hurt. Dairyland Power Cooperate is still assessing the damage at the site.