"Hang fire" is a term we've been using a lot lately - it's roughly defined as the snow left above the crown face once an avalanche has run.  In come cases, it can be triggered by a person.  If you trigger the hang fire, and there is enough snow remaining, it could result in a dangerous situation - you could get caught, go for a long ride, and possibly be buried.  If you're investigating an avalanche, you need to evaluate if it's safe to go in to look at the crown or not.  If in doubt, don't go.  (photo by Craig Gordon, Chalk Creek, Uintas)