Two children are among the six people who died in a Montana pileup after a Friday evening dust storm caused blackout conditions on Interstate 90, a major route in both Montana and the Western U.S. Montana Highway Patrol Sgt. Jay Nelson said investigators so far have found no other factors that contributed to the pileup that also sent eight other injured people to hospitals. The pileup was just west of Hardin, with additional ambulances called in from Billings to help. The identities of the dead and conditions of the survivors are not yet being released. The crash was reported around 4:30 p.m., as 21 vehicles, including six commercial semi-trucks, lost control in the dust storm that was fueled by gusts topping 60 mph (97 kph), authorities said. Nelson said there was zero visibility for a mile-long stretch during a peak summer traffic hour for those commuting home from work or traveling for outdoor recreation. It took more than six hours to fully reopen the road.