On November 4, 2012, a two-year-old boy, Maddox Derkosh, who had been sitting on the railing of the African wild dog exhibit, fell off the railing, bounced off protective netting, and fell into the enclosure, resulting in his death. The medical examiner subsequently determined that Maddox was killed by the 11 dogs that attacked him, not by the fall. Zookeepers immediately rushed to the area, firing darts to try and scare the dogs off, and police shot one particularly aggressive dog, which had refused to retreat from the exhibit when called. The other dogs were quarantined for thirty days but there were no plans to put them down. The prosecutor, Allegheny County, Pennsylvania District Attorney Stephen Zappala, calling the incident a "tragic accident", has stated he will not charge Maddox's mother, Elizabeth Derkosh, 34, who had lifted the visually impaired boy up on top of the railing to get a better view. He is still investigating whether the zoo is at fault due to any possible negligence. Since the incident, they replaced them with cheetahs. As a result of his death, Trucks for Maddox was created, to donate Maddox's toy trucks to children. It was also the second human fatality at the zoo.