▁before ▁being ▁h ired . ▁ ▁B irmingham ▁Pr ison ▁▁ ▁In ▁October ▁ 2 0 1 1 , ▁the ▁security ▁firm ▁spent ▁£ 4 9 9 , 0 0 0 ▁replacing ▁all ▁the ▁lo cks ▁and ▁keys ▁at ▁H MP ▁B irmingham . ▁A ▁G 4 S ▁sp okes man ▁acknowled ged : ▁" As ▁has ▁previously ▁been ▁extens ively ▁reported ," ▁this ▁loss ▁happened ▁ 1 8 ▁days ▁after ▁G 4 S ▁took ▁over ▁the ▁prison ▁in ▁ 2 0 1 1 . ▁ ▁On ▁ 1 6 ▁December ▁ 2 0 1 6 , ▁some ▁ 6 0 0 ▁prisoners ▁took ▁part ▁in ▁a ▁ri ot ▁at ▁H M ▁Pr ison ▁B irmingham , ▁a ▁prison ▁in ▁B irmingham , ▁England , ▁operated ▁by ▁G 4 S . ▁The ▁disturb ance ▁was ▁described ▁as ▁the ▁worst ▁in ▁Britain ▁since ▁the ▁ 1 9 9 0 ▁Str ange ways ▁ri ot . ▁The ▁national ▁chairman ▁of ▁the ▁Pr ison ▁Offic ers ▁Association ▁said ▁more ▁than ▁ 3 0 ▁officers ▁at ▁the ▁prison ▁had ▁quit ▁in ▁the ▁weeks ▁before ▁the ▁ri ot ▁and ▁that ▁further ▁prison ▁conv uls ions ▁were ▁in ev itable . ▁ ▁In ▁a ▁statement ▁to ▁Parliament , ▁Secretary ▁of ▁State ▁for ▁Justice ▁Elizabeth ▁Tr uss ▁said ▁that ▁ins u fficient ▁staff ing ▁lay ▁at ▁the ▁root ▁of ▁the ▁twelve - hour ▁B irmingham ▁ri ot ▁and ▁that ▁G 4 S ▁would ▁have ▁to ▁pay ▁the ▁costs ▁of ▁deploy ing ▁ten ▁highly ▁trained ▁public ▁sector ▁T orn ado ▁el