Picture this: It’s a sold-out night at a major sports venue. The energy is electric, thousands of fans are on their feet, and the excitement is palpable. But behind the scenes, security teams must be prepared for worst-case scenarios—an active shooter, a fire outbreak, or a hostage situation. How can security teams and event staff respond swiftly and discreetly while minimizing chaos? Venue Defender, a UX-driven emergency response solution, was designed to enable instant communication with 911 in less than three clicks while providing internal teams with structured alerts and standardized response procedures. This case study explores how a user-centered design approach transformed emergency response in entertainment venues.