Something that can kill somebody if it fails is
LifeCritical. Electrical appliances, boats, medical equipment, are all
LifeCritical. Software is rarely
LifeCritical; exceptions include life-support systems, power plant software, fly-by-wire systems, and patient monitoring software.
Although, I guess it's not part of the official definition of an Engineer, there's a definite sense that Engineers do
LifeCritical stuff. And yet if most software is
MoneyCritical rather than
LifeCritical...
As an example, I remember the
LeadEngineer for the
PrinceEdwardIsland bridge talking about how few people died on the project. Note that "few" is greater than zero. --
JasonYip