But when the sample is large enough, it still happens once in a while. In 2004, a CSB investigation showed that an entire chemical plant exploded after the interlock was bypassed by the supervisor password [0][1].

> The explosion occurred when maintenance personnel entered a password to override computer safeguards, allowing premature opening of the sterilizer door. This caused an explosive mixture of ethylene oxide (EO) to be evacuated to the open-flame catalytic oxidizer by the chamber ventilation system. The oxidizer is used to remove EO in compliance with California air quality regulations. When the EO reached the oxidizer it ignited and the flame quickly traveled back through the ducting to the sterilizer where approximately fifty pounds of EO ignited and exploded.

Apparently the supervisor who owned the password didn't receive any training on the nature of the process and the dangers of bypassing the interlock...

[0] https://www.csb.gov/assets/1/20/sterigenics_report.pdf

[1] https://www.youtube.com/watch?v=_2UnKLm2Eag