One time I was felling a tree having to squeeze it through some others . The tree being felled had a lot of dead in it. As it passed through ,brushing the others a piece broke off . I watched the tree hit the ground , as I walked towards the brush end to start cutting branches, the piece that broke off danced back down through the tree for at least 15 seconds before I clocked me in the head and knocked off my safety glasses. After felling now if I was brushing past other trees I stand back and look up before I proceed.