The probe into the death of a Markham couple in a garage fire has turned into a homicide investigation, police said Friday.

York Regional Police had previously said Thursday's fire -- in the garage at 2 Kentland St. near Markham Road, north of 16th Avenue -- was considered suspicious.

A neighbour called police shortly before 7 p.m. and reported hearing a loud explosion. Police said the damage to the home was mostly contained to the garage, which is where emergency responders located the couple.

The 42-year-old woman was pronounced dead on the scene, while her 48-year-old husband was transferred to Sunnybrook hospital in Toronto. He died of his injuries Friday morning.

Police said a post-mortem has been scheduled for Saturday.