Pressure's mounting on the Hodgman Government to hurry up with upgrades to the Ashley Youth Detention Centre after Friday's breakout.
Three boys climbed on the centre's roof, doing around $20,000 damage.
It comes in the wake of a scathing custodial inspector's report lashing the facility's security measures.
A spokesman says they're investing $7.3 million into the Deloraine facility, but has declined to comment on the latest drama as investigations continue.
Robbie Moore from the Health and Community Services Union has told Seven it follows years of neglect.
"This just further highlights how dangerous it is there, because of the layout of the facility and because of the lack of staff, and we need urgent action now," he said.
"The site needs an overhaul, its layout needs to be redone so that it's safe for both young people and the workers."