An Alcoa spokesperson says the fire started in an electrical panel inside the finishing department.
"We're a large facility," said Alcoa Spokesperson Jim Beck, "and with that we also have trained firefighters and also employees who are members of our fire brigade. They did respond quickly and helped be first responders to the scene. Then we did also receive some outside assistance from two volunteer fire departments as well."
All employees got out of the building safely. At least one person was treated after being overcome by the heat.