After searching for Lisa Gibson on foot, by helicopter and by riverboat, Winnipeg police had dive teams in the fast-running waters of the Assiniboine looking for the 32-year-old.
The strawberry-blond, bespectacled woman has been missing since Wednesday when her two young children were found in critical condition in their house. The two-year-old girl and three-month-old baby boy died in hospital.
Const. Eric Hofley said police were still hopeful Gibson was alive but had to explore the possibility that she might be in the river.
"We're always hopeful that Ms. Gibson will be located safely but, having been two days since she was last seen, it's time to at least expand the scope," he said. "We're certainly not giving up on finding her safely alive, but it's time to look at other possibilities and thus the dive unit being used."
Police had taped off a path leading from the quiet residential street where the home is located to the river. Officers have repeatedly asked anyone who might have seen Gibson to call police.
People have called in with potential sightings of the mom, but police are no closer to locating her.
"It has been two days and, due to the proximity of the river, it's incumbent that we explore that avenue as well," Hofley said.
There are reports the children were drowned in the bathtub. Autopsies have been conducted, but Hofley said police weren't releasing the cause of death.
"The investigation is ongoing."
The case has touched many in the city.
A group of mothers held a vigil Thursday night and a makeshift memorial of flowers and stuffed animals has sprung up outside the home. Many others have taken to social media to express their sadness and horror at the loss of two innocent young lives.
There are reports Gibson was suffering from — and being treated for — postpartum depression, but exactly what transpired Wednesday remains a mystery.
Her open Facebook page, which has since been restricted, was full of happy pictures of her two children: curly-haired toddler Anna and Nicholas, almost three months. The page included a family photo that appeared to be taken at a hospital shortly after the birth of Nicholas in April, along with a proud birth announcement.
The last posting was mid-June — a picture of Anna with the caption reading: "Man I love this kid."