The Iowa Department of Transportation has released footage from the overhead traffic cameras of yesterday’s multicar pileup crash. Warning: the video may be disturbing to some viewers.On Monday afternoon, both sides of Interstate 35 south of Ames were closed for hours after a chain reaction in the snowy southbound lanes grew and grew to claim more vehicles and victims, and the northbound lanes became access for rescue crews and tow trucks.“In my 26 years in law enforcement, I’ve never seen a pileup of this nature or this severe,” Story County Sheriff’s Capt.