TORONTO -- A senior manager at the prison in which a teenager choked herself to death while guards watched said Monday she was unaware of any confusion among officers about when to enter the inmate's cell.

Testifying at the Ashley Smith inquest, deputy warden Nicki Smith also said she could not remember being asked directly by frontline staff for direction on the issue.

"I have no memory of it at all," said Smith.

"I have no idea what I would have responded."

Smith, the current deputy warden at Grand Valley Institution in Kitchener, Ont., was acting in that position when Ashley Smith was first transferred to the prison in the spring of 2007.

The troubled inmate, who was prone to frequent self-harming, was 19 when she died in her segregation cell in October 2007.

The inquest has previously heard from several guards that they were under orders from senior management to stay out of Smith's cell as long as she was still breathing and had faced discipline for going in too quickly.

The deputy warden shed little light on the confusion.

Instead, she testified the call on when to intervene with the inmate, who frequently tied ligatures around her neck until she turned purple or lost consciousness, was up to the guards.

"The staff are highly trained, extremely professional," Smith told the inquest.

"I think staff would have known when to go in."

During her tenure at the prison at the time, Smith reviewed a dozen use-of-force reports involving the troubled teen.

In no case, did she find the force inappropriate, but her reviews identified several technical issues, such as improper use of a video camera to document the incidents.

The reviews did not look at what prompted guards to use force, Smith testified, nor did she react to concerns expressed by guards about the inmate's distressed appearance.

"Her behaviour, that's not really the focus of a use-of-force review," she said.

"I'm not reviewing what the officer has written. I'm reviewing whether the use of force was appropriate."

Smith was frequently unable to respond to questions, saying she could not remember details or discussions about the inmate's aberrant, self-harming behaviour.

She did recall deep institutional concern about the teen and the problems she was causing but offered little elaboration about what action was taken.

"Staff were becoming exhausted, burned out, tired. As a result of that, they were taking sick days," Smith said.

"We couldn't get enough staff at that time."

The senior manager said she did have some personal contact with Smith, saying she enjoyed speaking with her.

"She made me laugh a lot. She was very funny. She was a nice woman."

Smith said the tragedy points to the need for a mental health facility for inmates and urged hiring more staff with specific and significant mental-health training.