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A house blowing up out of nowhere
(i.imgur.com)
A catastrophic failure is a sudden and total failure from which recovery is impossible. Catastrophic failures often lead to cascading systems failure. The term is most commonly used for structural failures, but has often been extended to many other disciplines in which total and irrecoverable loss occurs, such as a head crash occurrence on a hard disk drive. Such failures are investigated using the methods of forensic engineering, which aims to isolate the cause or causes of failure. (Wikipedia)
Poorly planned and performed utility maintenance caused a gas leak and thus explosion. That’s usually the backstory behind gas leak explosions these days.