When a major issue occurs; something breaks or an important detail is missed, how quickly and effectively you communicate that problem can make a world of difference. There is a temptation to try and fix the problem before you communicate it up the line, and that's well-intentioned. But you must cap the amount of time spent trying to fix it before telling someone else.
The faster more people are aware of an issue, the better. It's also important how accurately you portray it. Don't sugar coat the problem thinking you can fix some of it before anyone notices. If you can't, then your lie is discovered and trust is broken.
Do not exaggerate the severity either. Painting a worse picture than what is actually occuring is also deceitful. There is such a principle as "under promise and over deliver," but when it comes to solving a problem it's best to be accurate and fast with your communication.