Corrosion could threaten structure of Gateway Arch

A report in The St. Louis Post-Dispatch reveals that the iconic stainless steel Gateway Arch is corroding. Reporter Nick Pistor reviewed engineering documents, which indicated corrosion, some of it feared aggressive, and severe discoloration of the stainless steel skin have long been present. The National Park Service allowed the newspaper to inspect a corrosion investigative report for about 40 minutes, but took away access citing national security concerns. The report, issued in 2006, called for a deeper study, for which the National Park Service says it only recently obtained funding.