An eight-metre high brick wall over the top of Villanova College's seniors area, classrooms and tuckshop at Coorparoo has collapsed, luckily while students are on holidays.
Villanova College principal Mark Stower said the timing of the wall collapse on December 27, 2016 could be considered "the grace of God."
"It is not my place to speculate what it would have been like during a school term," he said.
"But it happened at the quietest time of the year.
"And whether you call it the grace of God, or whatever, I don't' know, but obviously we are just very, very grateful."
The wall at the front of the Veritas Building – in the centre of the campus – suddenly collapsed as a multi-million building rehabilitation project nears completion.
Hutchinson Builders have since January 2015 been steadily replacing non-galavanised steel in the Veritas Building with galvanised steel.
Fairfax Media understands Hutchinson Builders did not use non-galvanised steel when the original construction was finished in 2012 at a cost of $11 million.
The Roman Catholic school's Veritas Building includes classrooms, staff rooms and study spaces and is used mostly by the school's senior school students and staff.
"The senior school has about 560 students and around 80 staff, so we would have around 400 people moving around that area, during any one day," he said.
"One section of the building facade collapsed."
Hutchinson Builders had fenced the area away from students for the past year as part of the building's longer-term rehabilitation work.
Villanova College has 1150 students and 81 full-time and part time staff in total.
The school on Tuesday sought an urgent meeting with the builders to learn why the wall had collapsed.
Hutchinson's national construction manager Chris Stevenson attended the meeting with Mr Stower on Tuesday afternoon.
"We have a number of engineers looking into it right now," Mr Stevenson said before the meeting.
"But it's just too early to tell why it collapsed."
Mr Stevenson declined to elaborate on why galvanised steel was not used in the original construction.
"That's a six-year old story from a long time ago," Mr Stevenson said.
However he insisted all Hutchinson-constructed buildings now used galvanised steel on the site.
Hutchinson Builders director Greg Quinn has been briefed on the incident.
This rehabilitation work is being done at no expense to the school, Mr Stower told Fairfax Media.
Villlanova College began classes in Coorparoo in 1953 and is one of Brisbane's most respected schools.
Mr Stower said while there was no risk to students, he was very concerned the brick wall had collapsed at all.
After Tuesday's meeting Mr Stower said Villanova College still did not know why the entrance-way to the Veritas Building had collapsed.
"There is still some speculation on that and obviously we are waiting on the builders and the engineers to give us that report," he said.
Mr Stower said the school's engineers were not prepared to speculate on the reasons for the brick wall collapse.
He said Hutchinson would have the site cleared by the time school returned on January 23.
"The repair work will not be finished by January 23, but they will have all that area where the bricks fell cleaned up and fenced off, as it has been for the past 12 months."
Villanova College's past students include Attorney-General George Brandis, former deputy premier Paul Lucas, prominent actor Eugene Gilfedder and former Wallaby Andrew Slack.
It is an independent Catholic school for boys Year 5 to 12.