Anyone who says he/she has never had a failure is not being honest with themselves.  We all have failures from time to time. The important thing is to be able to handle the failure with grace.
Recover from the failure and get everything working again.  Acknowledge the failure and why it happened, document it fully so it will not happen again.
Just look at Apollo 13, all of the engineers worked together to deal with a failure and found a way to bring our men back home, today that failure is also one of NASA's greatest accomplishments.
I seem to remember a quote "if you have not made a mistake you have not done anything" don't know who said it but I often tell it to the young ones who have made a mistake and feel bad about it.