The Arecibo radio telescope, one of the most iconic scientific instruments of the 20th century, collapsed on December 1, 2020, in Puerto Rico. Built in 1963, it was the world's largest single-dish radio telescope, with a massive 305-meter metal reflector designed to capture radio waves from distant parts of the universe. The telescope was supported by a network of cables suspended between three towers, with a 900-ton platform above the reflector. The collapse happened in less than thirty seconds when its final supporting cables failed, causing the platform to fall directly onto the reflector and severely damaging the structure. The cause of the collapse was not a sudden storm or simple rust, but a slow, hidden form of degradation called creep fatigue under corrosion. This process creates tiny internal cracks in steel over time, even without visible signs on the surface. The first warning signs appeared months before the collapse, when an auxiliary cable snapped, damaging part of the reflector. A second main cable then broke, prompting engineers to work urgently to assess the telescope’s stability. Despite efforts to reinforce the structure and analyze its condition, the damage was deemed irreversible. The collapse of Arecibo was not just a loss for astronomy—it highlighted a broader issue affecting many large infrastructures worldwide, such as bridges, dams, and communication antennas. These structures often rely on materials that are strong but not immune to long-term wear and environmental stress. The incident has prompted engineers to reconsider how they monitor aging infrastructure, seeking better technologies to detect internal damage before it becomes critical. The fall of Arecibo marked the end of an era. Once a symbol of human curiosity and scientific achievement, the telescope now lies in ruins, a reminder of the importance of anticipating hidden vulnerabilities in our built environment. The event has sparked new discussions about how to ensure the safety and longevity of large-scale structures in the future.