From a Go game last evening: the large white group on the right side is dead.
White was doing OK with a good territory in the lower left and another along the top, but I poked at his shape on the right side and my stone along the right edge of the board put 3 stones in atari. If white defended the stones, my next move would destroy his eye space. White could not save his stones and the game was over.
I love the drama of a big kill in Go.