I am male,early thirties and work at a famous supermarket chain here in UK. We wear uniform of dark trousers and blue chequred shirt with black undervest. The other day i was styacking shelves with a male colleagure and this lunatic came up behind us and grabbed out heads and cracked them really hard together. We slumped down,dead limp,on top of each other. The lunatic was overpowered later in the store.