Complex was built. This new building contained five classrooms, a library, and a 300-seat lecture hall. The construction of this building was an important part of the zoo's history because it signified the zoo's dedication to conservation and education. In 2000, the AquaZoo underwent a $17.4 million renovation, and was renamed the PPG Aquarium. This new aquarium is twice the size of the original AquaZoo. In 2002, the Education Complex was expanded to include a second story, providing more classrooms, teacher resource areas, and an animal holding area. This expansion was made possible by the Scaife Charitable Foundation and by donations from senator Rick Santorum. On November 19, 2002, elephant keeper Mike Gatti was killed by one of the zoo's elephants. Gatti, 46, was killed while attempting to encourage the elephant to move to a different part of her enclosure. She butted him with her head, crushing him against the ground and killing him instantly. This was the first instance of a human fatality at the zoo, although there had been injuries. In 2006, the Pittsburgh Zoo completed Water's Edge, a marine exhibit that allows guests to have close encounters with polar bears, sea otters, and sand tiger sharks. 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, the zoo replaced the wild dogs 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