A pair of 23-month-old twins -- a boy and a girl -- died in a house fire in Mackenzie, B.C. early Tuesday morning.

Just three weeks shy of their second birthday, the twins were "a joy" to their parents and "to everybody that they came into contact with," their grandmother, Debra Baxter, told CTV Vancouver in a telephone interview.

"Just such joyful children," she said, her voice breaking.

Five family members were inside the home when the fire broke out at about 7:30 a.m. local time in the small northern community, about two hours from Prince George, B.C.

The twins, Gabrielle and Joseph, were in their bedroom on the second floor. When firefighters and police arrived on scene minutes after the blaze started, the house was fully engulfed in flames.

The children's parents, firefighters, police and a civilian tried to get inside the home to save the twins, but the fire was too aggressive, the RCMP said.

The parents, along with a three-old-child, were able to escape and are being treated at the Mackenzie District Hospital, RCMP Const. Lesley Smith said in a telephone interview Tuesday.

Baxter said she received a devastating phone call from her daughter after the fire.

"I wish I would wake up from my nightmare," she said. "It doesn't sink in. You close your eyes and you think: ‘Please be a dream, please be a nightmare.'"

The RCMP has handed over the investigation over to fire officials and the coroner. The cause of the blaze is not yet known.

"It's a small close-knit community, everybody knows everyone in this community and I understand that a lot of neighbours came out to help but unfortunately the fire was just too bit too aggressive and we've lost two little ones," said Smith.

The Mackenzie area was without normal 911 service Monday night after a logging truck ran into a utility pole, but service was restored by 2 a.m. Tuesday morning.

With a report from CTV Vancouver's Shaheed Devji