Contraband Cellphone Video Shows Inmate Escape

It's 2017. Why do they even BUILD jails with cells with vents larger than 6" square?

Honestly, I'd build them with big vents, but then have a misleadingly easy turn/drop that leads to an inescapable hole.

"Bill, cell 9 is empty"
"Oh? The guy in it must have 'escaped' through the vent. Ha ha. 3rd one this month."
"Do I hear someone screaming for help? It's really faint and getting weaker..."
"Nah, that's just the wind. It'll quiet down after a couple of days. Let the warden know cell 9 is vacant again after I screw the vent cover back on with these easily-removed screws."