More than 200 inmates are being transferred out of Birmingham's Winson Green prison after a 12-hour riot left half the prison uninhabitable.
An investigation has been launched into how 600 inmates were able to overwhelm guards and take over four wings of the jail, setting fires, raiding medicine stores and causing extensive damage.
Sunday morning (local time), the riot squad left the prison, and 240 inmates were relocated to nearby prisons. As they moved out, a dump truck moved in - a sign of the extent of the damage inside.
Two of the prison's four wings remain uninhabitable.
Photographs apparently taken inside the prison on Saturday appear to show inmates wearing helmets belonging to prison officers.
G4S provides the staff for the Birmingham prison. They are a security company operating in 100 countries globally. In New Zealand, G4S provided electronic monitoring services to the Department of Corrections until 3M took over the contract in 2015.
The riot follows on from other recent instances of violence in UK prisons. In October, a 21-year-old inmate was stabbed to death at North London's Pentonville Prison. Inmates rioted for six hours at Lewes Prison in October and 200 prisoners rioted at Bedford prison in November.
The UK's head of prison service, Michael Spurr, acknowledges an issue with staffing and says they are actively recruiting more staff.
"Absolutely, we need more staff in our prisons. That why we've been given the investment to recruit more staff," he told ITV News.
Justice Secretary Liz Truss is likely to face serious questions about the private company running the jail and whether successive budget cuts have left staffing levels at all prisons too low.
ITV / Newshub.