Blades snapping off and hole(s) in nacelle hardly qualifies as an engine failure. More like severe damage.
WHAT!! You have to be kidding me right!?
Holes in the nacelle means the blades that did snap off didn't stay inside the engine. That is usually called an "un-contained engine failure"... Quite serious stuff indeed, especially if that blade decided to break off in such a point of its rotation that it got aimed at the fuselage, a passenger's head or any major structural parts.