Construction began in the summer of 1993 at the west end, employing the conventional mining technique of drilling and blasting due to the loose mixture of materials. More than 75 tons of explosives were used and mining progressed about a mile into the hill. East end construction began in August 1994 with a customized tunnel boring machine. About a thousand workers from 230 construction firms were involved in the 18-mile westside MAX line, including those who built the tunnel and installed the reinforced concrete liner, tracks and wiring. One worker was killed while operating equipment.