When the Captain said one of the two engines on our easyJet flight tonight wouldn't start, quite a few passengers did not want the other one to start either - they wanted off!Seems they're bump-started. The engines, I mean, not the passengers who eventually sat down again. A high pressure jet of air sets the blades spinning. It was this jet which didn't work, so the engine wouldn't start.
Of course, not starting is an easier fault to deal with than suddenly stopping.