Little Joe the western lowland gorilla’s single 2003 breakout from Boston’s Franklin Park Zoo remains his only recorded escape, and traders assign just a 5.6% chance he repeats the feat before July 31 because modern AZA-accredited facilities feature reinforced barriers, moats, and surveillance that have prevented similar incidents for decades. At 33, the silverback is older and less agile than during his youthful spree, while his upcoming transfer to the Pittsburgh Zoo is a meticulously planned breeding move under strict professional oversight rather than an unsupervised relocation. No recent security lapses or behavioral red flags have surfaced in credible reporting. An unexpected transport accident or sudden health-related enclosure change could theoretically create a narrow window for trouble, yet the overwhelming consensus reflects zoos’ strong track record of containing high-profile primates once initial upgrades are in place.