Imagine the engine fire at 35 000 ft. Yikes
No big deal. The pilots will shut the engine down and stop the fuel flow and activate the fire suppression system in the engine. They will then land the plane using just one engine or in the case of a Jumbo 3 engines. What you do not want is a turbine disintegration. That is really bad. The engine's turbine blades then become shrapnel. Southwest had one disintegrate in flight and it killed a passenger.