FAIRFAX, Va. (AP) - The Virginia Department of Transportation is investigating what caused a 30-foot sign to collapse onto Interstate 66 in Fairfax. The sign fell Saturday afternoon into the eastbound lanes near Monument Avenue. It struck a pickup truck, but nobody was hurt. VDOT Commissioner Greg Whirley says the department will take the necessary actions to make sure its structures are safe. There were strong wind gusts Saturday afternoon, but it's not clear that they were a factor.