MONTREAL -- A Quebec father of three young children was struggling Monday to make sense of the tragic death of his three children.

The children -- Lorelie and Anais, aged five and two, and their-four year-old brother Loic -- were found dead the previous day after a 911 call from their mother's home in Drummondville, a town about an hour outside Montreal.

Patrick Desautels said the deaths left him speechless. He asked journalists to allow the family to grieve in peace.

"We are currently together as a family and this tragedy leaves us without words," the grief-stricken father wrote in a statement. "The police investigation will tell us more about the circumstances of the tragedy. What has taken place is inexplicable."

Desautels added that he loved his children and will miss them for the rest of his life.

The father was scheduled to meet with reporters near the family business in Ste-Christine, Que., on Tuesday afternoon.

The circumstances surrounding their deaths remained mysterious Monday. Quebec provincial police said they hoped that the mother of the three children -- Desautels' ex-wife -- could deliver some answers.

The mother, 33, was also transported to hospital for unspecified reasons. She was described as an "important witness" by police. Although her life was not deemed to be in danger, she had not met with investigators on Monday afternoon.

"Once her health improves enough for us to meet her we will do so -- as soon as it's possible," said Sgt. Daniel Thibaudeau, a provincial police spokesman.

"All I know it's that it's unable for us to meet her right now. Once the doctors give us an okay for that our investigators will be right there to get a preliminary statement."

People left a makeshift memorial of flowers and stuffed animals outside the house Monday. Among the visitors to the residence was one friend of the mother's.

The friend described the deaths as a shock.

"She was a good person, she was a kind person who loved her children and never could I have imagined she'd do something like this. It's a shock to everyone," said Nancy Latraverse, standing outside the home.

"You can't predict something like this is going to happen."

Police have still not said how the children died or where they were found inside the second-floor unit of a brick duplex in Drummondville, about an hour outside Montreal.

Meanwhile, Thibodeau said investigators were also meeting with other witnesses to figure out more about the circumstances surrounding the deaths.

Police questioned the victims' maternal grandmother. Reports said she was the one who made the grisly discovery Sunday.

Court records said the mother had a run-in with the law about a year ago.

Quebec provincial police were called to investigate when the mother allegedly took off with her then 14-month-old daughter after losing out in a custody battle with her ex-husband. Media reports at the time said police were able to track her down a day later and place her under arrest without incident.

She is scheduled to return to court in that case next month, court records show.

Police would not confirm who had custody of the three children or discuss reports that the mother had limited supervised access.

Autopsies were scheduled to be performed on the young children later Monday to determine how they died, Thibodeau said.

The Quebec coroner's office said it wouldn't reveal any information for the time being.

"It would be unwise to reveal the fragmented information that could change and potentially damage a criminal investigation," the office said in a statement.

"For these reasons and for the sake of thoroughness, the coroner's office will not comment on the tragedy."