PONTIAC (WKZO) -- The roof of the Pontiac Silverdome is no longer inflated as crews prepare the arena for a renovation project.  Earlier this week, engineers turned off the giant fans which kept the fabric dome inflated as part of the plan to put up a hard roof with solar panels.  Silverdome officials say while there are no shows planned at the site in 2013, they believe the new roof will help the stadium become more competitive for different types of events in the future.