SASKATOON -- Prince Albert police have one man in custody in connection to a triple-homicide that left a boy and his two grandparents dead.

The chief of the Prince Albert Police Service said a man had been arrested but so far no charges have been laid.

“We want to offer our condolences to the family of the victims and those who knew them,” said Chief Jon Bergen. “We can’t imagine how extremely difficult this tragedy will be to heal from and process.”

Officers were called to the 300 block of McArthur Drive in the city’s west-end on Sunday afternoon. There, police say they discovered the bodies of Denis Carrier, his wife Sandra Henry and their grandson, Bentlee.

Bentley’s little sister, Kendrah, age five, was airlifted to Edmonton in critical condition.

Autopsies are scheduled for later this week to confirm the causes of the deaths.

The chief said to reporters in an update Tuesday afternoon that investigators don’t know exactly when the killings occurred.

“We responded Sunday around 4 p.m.,” said Bergen. “The evidence would suggest that the crime happened anytime between Friday night and into that time that we responded.

GoFundMe pages have been set up for the family of the victims.