DETROIT (AP) — U.S. safety regulators are investigating whether a recall of 156 fire trucks last year was enough to fix a problem with aerial ladders that can unexpectedly fall. The probe covers trucks from the 2000 to 2012 model years made by Ohio-based Sutphen Corp. The National Highway Traffic Safety Administration says two ladders fell after the trucks were recalled in May of last year.Read more on NewsOK.com