HAYDEN COOPER: He too had his worries at the time.
ALLEN POWELL: Virtually every child, every student in this school would have been exposed to whatever the contaminants are there, yep. At one, probably every single day that they were here.
Former science teacher Allen Powell worked at Camden High School in Western Sydney, New South Wales in the 1980s and '90s.
He says he had his worries about the school at the time.
"After about 1988 when we had a lot of rain here, stuff started oozing out of the ground which was black and sticky-ish."
The school was closed in 2001 after contamination was discovered in soil underneath classrooms.
The school was built on the site of a gasworks that had been in operation since 1911.
Dozens of former Camden High teachers and students have became ill and some have died.
"I'm really upset, very saddened by it. It's very distressing. I wish I'd made more noise, I feel guilty about it." Mr Powell said.
Lawyers say 70 people have joined an investigation into Camden High School to determine the cause of a range of recent illnesses.
The group includes people with various forms of cancer, brain tumours and children with birth defects.
Some members of the group represent former teachers and students who have died.
Lawyer Jim Marsden says the complaints could lead to a class action against the NSW Education Department.
"Ultimately whoever is responsible must be held accountable," Mr Marsden said.
Several former students blame their illnesses on the old gasworks site.
The contamination at the high school was discovered in 1995 and contained the following year.
Reports from the era include lists of chemical substances which were found such as benzine, banzoapyrene, cyanide and polycyclic aromatic hydrocarbons (PAH).
"There was always an egg smell and I always thought that the Bunsen burner gas taps had been left on or leaking, but I didn't know until after I left school that this was a gasworks," former student Rachel Dowling said.
Ms Dowling attended the school from 1985 and now has thyroid cancer.
But research director at the NSW Cancer Council, Freddy Sitas, has urged caution.
"These investigations can go on for three or four years, and nine out of 10 of them turn out to be nothing.
"So it is important not to raise expectations when investigating a cluster and not to call it a cluster when it is not so."
Former Camden High School teachers and students are involved in a potential class action.
They believe cases of cancer, tumors and birth defects may have been caused by exposure to toxic chemicals at the school.
Camden High School Art teacher Dale Hodges, 45, died in 2007 of thyroid and ovarian cancer.
Her partner Glenn Carson says Dale was fit, and had no family history of cancer.
"She trained hard, she worked hard, she wanted to live and she wanted to teach and it didn't happen," he said.
Ms Hodges taught at the school for 18 years.
For much of the time she taught in a classroom directly on top of the site of the former gasworks.
She kept records of the contamination uncovered in 1996.
The records include a letter from the Environmental Protection Authority warning of high levels of contamination.
The letter was addressed to the NSW Education Department.
Some remediation work was done a year later, but the school was not moved until 2001.
Mr Carson says it should have happened sooner.
"You turn up to your workplace thinking it's safe - which is what a workplace should be - but obviously this workplace wasn't safe," he said.
"We just need answers.
"You need to be able to find out why in '96 they didn't do something more drastic than wait until '97 for a start, wait another year before they did anything at all, then wait another four years until they got the land at Cawdor."
Lawyers are preparing a class action against the Education Department on behalf of a group of 195 people.
Camden High ex-student Leonie Curry, 41, is the lead plaintiff for the case.
Mrs Curry set up a Facebook page and was swamped with feedback from former students who suspect the contaminants at the site made them sick.
Those involved acknowledge that proving the cause of their illnesses may be impossible.
Nonetheless, Glenn Carson, who is still struggling with the death of his partner, wants an official inquiry.
"It'd be nice just to be able to find out what happened, why it happened and how it happened," he said.
"If it could've been prevented, why wasn't it prevented?"