Agreed with the above although I do have one caveat to add. Once upon a time, I got a bit slackish and figured Nah.. I dont need to check that blowoff hose today, it wont be a problem....
Went out later that evening and when I went into the brew area, the overwhelming smell of fermentation alerted me that something might be amiss.
I turned the lights on and found an absolute disaster. The airlock had plugged up and the bucket was BRAND NEW with a very slight chance that the seal on the lid was gonna give way.
Preliminary visual inspection demonstrated that when the pressure blew that airlock and o-ring gasket (which I never found) that the krausen shot outta the hole like a freakin geyser and I actually had formed krausen stalactites and stalagmites on the floor and ceiling in the room.
Luckily my brewing area is kinda easy to clean (if it had happened in the house, I may have been forced into divorce).
Moral of the story: Never totally dismiss an airlock that has yeasty buildup....;-)