Water leaking through the ceiling of a Chinese national research facility might have destroyed a new-generation quantum computer under construction if not for the quick action of students working late. The incident has brought attention to the fragility of the hi-tech machines, but also the vulnerability of the humans who design and operate them. Around 2am on Sunday, 26-year-old doctoral student Zhong Hansen was working at the Hefei National Laboratory for Physical Sciences at the Microscale in Anhui province when he noticed water spilling into his lab, according to an official investigation. The lab was filled with expensive equipment, some...