PITTSBURGH — A safety committee had concerns about the Pittsburgh Zoo exhibit where a 2-year-old boy was mauled to death last year by wild African dogs, according to court papers filed in a civil lawsuit.

Maddox Derkosh fell from an open viewing area into the exhibit, and the attorneys representing his parents say the zoo safety committee expressed concerns as early as 2006.

The boy’s parents have sued, but the zoo says the mother was negligent.