I'm having troble with a little game i am making. You drop bombs and the ground gets blasted away. This is what happens..

A movie clip is duplicated and accelerates downward. when it contacts the ground it goes to a different frame with a black color (the same as the background) and stops. This gives the effect of the ground being blasted away (like worms). The problem i have is when the bomb hits the ground the others need to test the ones that have blasted the ground away and therefore travel through them as well. I used a loop to detect the ones on the ground already, but i cant figure out how to make them pass through the others smoothly.

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