New details have emerged about a family that is at the centre of a tragic incident in Scarborough that has left two young children dead and their mother critically injured.

Officers were called to a building on Glamorgan Avenue, near Kennedy and Ellesmere roads, at around 7:30 p.m. Sunday for reports that a woman had fallen from a balcony.

Police said officers arrived to find a 25-year-old woman on the ground outside the apartment building. The woman had suffered critical injuries but was conscious at the time, Insp. Terry Browne told reporters at a news conference on Monday morning.

“As a result of information they received at that location, they attended a unit within that building to check on the wellbeing of two young boys,” Browne said.

“Officers had to force entry into the unit. When they arrived inside, they did locate two young boys who were vital signs absent. Both were transported to local trauma centres, different trauma centres, but unfortunately both of them succumbed to their injuries.”

The boys, ages 4 and 5, were brothers and the children of the woman critically injured in the incident, Browne confirmed.

Costa Collias, yianni, mimi

He said their mother remains in hospital in critical condition and will be undergoing surgery shortly.

Neighbours tell CTV News Toronto that the boys were named Yiannis and Mimi and that their mother was Vanessa Collias.

The neighbours say that the boy’s father, Costa Collias, otherwise known as “Gus,” died on Dec. 1 following a battle with Leukemia.

"They were cute little four and five year olds. They always said hi to me all the time and that’s the picture I saw all night long last night was their little faces going 'hi,'" neighbour Steve Rafferty said of the children while speaking with CTV News Toronto on Monday.

Scarborough, critical, children, woman

Browne said the boys did not have any obvious signs of trauma when they were discovered but their deaths are being treated as “suspicious.”

“Autopsies for both of these young boys are not expected to occur before Wednesday of this week but given the circumstances and nature of this investigation, even its early stages, the homicide and missing persons unit has taken lead of this investigation,” he said.

“Certainly the scene presentation right now suggests that we in fact should be leading this investigation. The medical examiner will tell us conclusively how these boys may have met their fate.”

He noted police have "some information to suggest" that the boys were "healthy and well" earlier that day.

Browne added that police do not believe the woman’s fall from the balcony was accidental.

Insp. Terry Browne

“I don’t believe at this stage that she was assisted in falling over the balcony. I don’t know what her motive was when that occurred but certainly I have no reason to think that someone was with her at the time she fell,” Browne added.

“My understanding is her injuries are quite serious but she is stable right now. I suspect she is likely going to survive.”

A custodian, who identified himself as Jay, told CP24 on Monday that he bumped into the woman in the elevator just last week and she confirmed that the father of the boys had died. 

Vanessa and Costa Collias

Jay described the couple and their kids as a “happy family.”

“I wave at them every time they come down,” he said. 

With files from CTV News Toronto's Janice Golding.