peter hiett , a decorated former prison guard at feltham young offenders institution , said staff would put inmates in a cell padded with mattresses and leave them to fight out any differences .
the 49-year-old , who worked at the jail for eight years and was commended for bravery , said some workers would even stay and watch the battle unfold , while others ` turned a blind eye to it ' .
if they saw another gang member all hell broke loose , their wars do n't stop when they 're behind bars .