When switching on the oxygen pumps, there was an explosion on board of the Apollo 13 space craft. A short circuit in a small module led to an explosion rendering most of the space craft useless.
For days, the crew frantically worked in cramped quarters trying to return to Earth. Tensions ran high, but, instead of blaming each other for the mistakes they made, they concentrated on the system of the space craft and how to work with what was left of it. Only that broad, holistic focus on the system let them survive.