The family of a 20-year-old Brampton man who killed himself while under suicide watch plans to sue the hospital where he died for $12.5 million.

Prashant Tiwari died by suicide at Brampton Civic Hospital last year, 10 days after he was placed under around-the-clock supervision as a suicide risk. His family says the hospital failed to check on him regularly, and he found the means in that time to end his life.

Prashant's father Rakesh Tiwari says he now plans to sue the hospital and six staff for the wrongful death of his son. This comes after Rakesh’s request for an official inquest by the chief coroner of Ontario was refused last year.

Family lawyer Michael Smitiuch says Prashant's death is indicative of a "systemic" problem in Canadian hospitals, that stems from current training, protocols and procedures.

"Rakesh took his son to the hospital because he was hurting himself," Smitiuch told CTV's Canada AM on Wednesday. "He thought the hospital was a safe haven, and it wasn't."

The Tiwari family is also hoping to raise awareness about mental illness, Smitiuch said.

Prashant struggled with suicidal thoughts and was hospitalized after he cut himself with a knife last summer. Ten days after he was placed under suicide watch, Prashant was found dead in the shower area of the hospital. He had hung himself with the help of a chair.

"The understanding was that Prashant would be provided with supervision every 15 minutes. That was the protocol," Smitiuch said.

"For over two-and-a-half hours he was left unsupervised in a shower area" Smitiuch added. "In that shower area, he was provided with a chair."

That chair "should not have been there," according to chief psychiatrist Dr. David Koczerginski of the William Osler Health Group, the organization that runs Brampton Civic Hospital.

"Any chair that would be in the shower would be an error, a mistake," Koczerginski told CTV's W5 in an interview last year.

The Koczerginski interview was part of a W5 investigation that uncovered hundreds of suicide deaths in hospitals across Canada, spanning a ten-year period.

Smitiuch says those numbers are part of the reason the Tiwari family is pushing for an official inquest from Ontario's top coroner. The Office of the Chief Coroner previously declined to conduct an inquest, but the Tiwari family is hoping it will reconsider.

"There has to be better training in terms of supervision," Smitiuch said, adding the family also wants the hospital to put patient records under tighter controls after several medical staff allegedly accessed Tiwari's files without necessity.

But even with careful supervision, Ontario's Health Minister Dr. Eric Hoskins says it's not possible to guarantee a hospital patient will not take their own life.

"Regrettably, when it comes to suicide, I think there’s no guarantee anywhere, at any time. But our responsibility is to do our absolute upmost to minimize that risk," he told reporters Wednesday.

The William Osler Health System says it has already looked into the death.

"We have shared all findings of our review of the case with the family, as well as the actions we have taken to address the recommendations," spokesperson Cara Francis said in a statement.

The organization did not specifically comment on the Tiwari lawsuit when reached by CTV News this week.

"While we do not comment on any individual patient case, we have and continue to express our sincere condolences for the family's loss," a hospital spokesperson said. "The entire Osler community has been deeply affected by the circumstances surrounding this death."

The William Osler Health System says it has not received notice of legal action from the family.

"When we receive it we will respond through the appropriate legal process," a spokesperson said.

With a report from CTV Toronto's Ashley Rowe