Zinc creep in cable spelter sockets brought down the Arecibo telescope in 2020

A National Academies report found that long-term zinc creep in cable spelter sockets caused the 2020 collapse of Puerto Rico's Arecibo Observatory telescope, a failure mode with no documented precedent despite zinc sockets being used for over a century. The deterioration accelerated after Hurricane Maria, and the report suggests electromagnetic waves from the telescope itself may have further weakened the zinc through electroplasticity. The report recommends increased monitoring and dedicated funding for condition maintenance at aging research facilities to detect unprecedented failure modes.