The piercing sound of blood-curdling screams prompted neighbours to call 911 early Monday morning, and when police finally arrived at 81 Rotary Drive near Sheppard Avenue and Meadowvale, they made a horrific discovery that tainted an otherwise beautiful Thanksgiving Day in the city. 

Police found two women dead inside the home, while a third managed to escape. Not long after the grim find, a 31-year-old man who didn't live at the residence was placed under arrest.  He has since been identified as Nathaniel O'Brien, of Toronto, and he's facing two counts of first degree murder among other charges.

The victims have also been identified as Susan John, 43, of Toronto, (pictured left) and Saramma Varughese, 65, of Toronto. (pictured right)

The 911 call was made at around 6:50am . 

"(I heard a) terrifying scream, a horror scream," one neighbour told CityNews.

Reports suggest the women may have been stabbed to death, but the cause of death won't be confirmed until post-mortem examinations take place on Wednesday.

"We received a radio call for unknown trouble at this address...Officers arrived on scene. They entered the premise and they located two female victims suffering from obvious trauma," confirmed Sgt. Andrew Ecklund of Toronto Police.

It is believed the third person, who managed to escape with her life, was injured, although the extent of those injuries isn't known.

Blood was apparently discovered on the front doors of several homes in the area, after the surviving victim ran from door to door trying to get help.

Neighbours described their street as quiet and tidy, and said nothing like this had happened there before.