The probe into a house explosion in Kitchener is now a criminal investigation.
Waterloo Regional Police say the woman who was killed was the victim of a homicide.
She has been identified by police as Edresilda Haan, who was 58.
The cause of death has not been released.
"I can't provide any further information as the investigation is in the infancy and continuing, however we are confident that her death is the result of a homicide." Waterloo Regional Police Inspector, Mike Haffner told an afternoon news conference at police headquarters.
Police also say the cause of the explosion, which has not been determined, is considered suspicious.
A man, 58, who was injured in the blast, remains in a Hamilton hospital.
"The individual that was airlifted to hospital ... with critical injuries ... did reside in the residence, he is related to Ms. Haan." explained Haffner.
The explosion happened just after 8 a.m. on Wednesday at a home on Sprucedale Crescent.
Residents reported hearing it kilometres away.
One home was demolished and two others suffered significant damage.
Haffner adds there will be an increased police presence in that neighbourhood well into next week.
Anyone who has any information is asked to call police at 519-570-9777 ext. 8419.