Gatineau Police have confirmed a young brother and sister who were pulled out a burning Gatineau apartment Saturday evening have now died in hospital from critical injuries.

Firefighters found the 12-year-old twins, Gabrielle and Jacob Rondeau,  unconscious in the burning second-floor apartment on Marengere road, after being called there shortly before 11 p.m.

The siblings, found on the floor of the unit, needed to be resuscitated. They were rushed to the Gatineau hospital with serious, undisclosed injuries. The boy was transferred to CHEO for treatment.

The twins’ 17-year-old brother Daniel Rondeau had been babysitting them.

He told CTV Ottawa after his brother and sister went to bed, he left them home alone briefly when he stepped out to get pizza with his girlfriend.

He said they were gone about 20 minutes.  When they returned, the fire was already raging, with firefighters on scene fighting the flames and thick smoke.

"We came back, there was fire everywhere," said Andrea Miller, Rondeau's girlfriend.

A man who was visiting family across the street noticed the flames and smoke coming from the building, he called 911.

“It just spread really fast, I'm talking 10 seconds max, then everything was just burning,” said neighbor Andre Valiquette.

Valiquette noticed smoke inside his unit, initially thinking it may have been coming from his dryer. He realized it was actually coming from his neighbour’s apartment.

He ran to their back door, where he could see flames in the kitchen.

“I could see through the door, and I saw the flame literally light up, and it just blew, just a big ball of fire,” he said. “I ran, I tried to go inside because I knew the kids were upstairs, I think I made it four feet in the house, then I had to turn around.”

Fire officials said 22 people were evacuated from the building, including Valiquette, his wife and seven children.

Valiquette says the ordeal has left them rattled and worried about the condition of the siblings.

He said Rondeau adores his younger sister and brother and doesn’t want him to be blamed for the incident.

“He loves them more than a dad can love his own kids, there's no way anybody can blame him,” he said.

Gatineau fire officials say the fire may have been caused by unattended cooking.

Damage was contained to the apartment where the fire originated. Damages are estimated at $100,000.