SYDNEY, Nov 8 -  Banksia Road Primary School, in Greenacre, reopened on Wednesday, a day after the fatal incident.

Two eight-year-old girls and a nine-year-old girl remain in hospital in a stable condition.

NSW education department secretary Mark Scott says a coronial inquiry will examine whether a car park should have been near classrooms.

"There is car parking in schools ... staff car parking in schools around the state," Scott told reporters.

"In our experience, we don't recall any incidents like this at all, but we will take specialist advice and review that advice carefully when it comes to hand."

Education Minister Rob Stokes said there was a regular maintenance inspection of the school building earlier this year.

"No structural issues were identified and no risks were identified according to the advice I have," he said.

"This was a circumstance that was outside what had been anticipated or experienced at schools in the past."

Scott said the timber school building had been on the site since the 1960s and the adjacent car park "has been long established there as well".

The minister said some "bonded asbestos" was disturbed during Tuesday's crash but had since been removed.

Air monitoring is in place and "no health issues have been identified".

Answering questions about whether the school had a defibrillator, Scott said the department had followed the advice of NSW Health on defibrillator usage, and his staff had done "exactly the right thing" following the crash.