At the Mica, Washington, brick plant of Bellevue-based Mutual Materials, hacker Scott George loads a 16-inch green brick onto a kiln car. Each car carries a tag that describes the style and color of the product being fired. Capable of producing 40 million bricks a year, the plant sits on 400 acres and ships around the world. Many of Seattle’s iconic buildings, including Safeco Field, were built with bricks from Mutual Materials, the largest supplier of masonry and hardscape products in the Northwest. Among the kilns on the Mica property are two beehive kilns that are more than a century old and still being used to fire tiles for chimney flues. Click through to see more images.