I think you and google are missing the difference between Jail, Prison, and Holding Cells. the combined unit you show is only common in Prison and long term county lvl jails; for cities/town/district jails and holding cells they may or may not even have a toilet as they are designed around an 4-8hr stay limit.
Most likely what happened is that a district detention got overwhelmed and just placed people in secure locations and lost track of them. Hanlon’s razor.