Originally Posted by frogfree
You probably either over-pitched the number of yeast or fermented too warm. Make sure to keep the fermentation temperature in control (below 70F for most ales and below 50F for most lagers).
You probably didn't overpitch unless you reused a yeast cake.
I've had buckets that didn't seal too well, but when fermentation was extra vigorous, it pushed through the airlock too. Sounds like everything is fine, give it some time to finish up.