The Christmas Day house fire that killed Madonna Badger's three daughters - Lily, Grace and Sarah -- and her parents - Lomer and Pauline Johnson -- was caused by discarded hot embers removed from the fireplace, authorities report. Only Badger and her boyfriend, contractor Michael Borcina, escaped alive.

The fire appears to have been caused by hot fireplace ashes and embers, which had been discarded, said Barry Callahan, chief fire marshal in Stamford, Connecticut.  Officials said that everyone had awakened after the blaze erupted and was trying to escape.

According to preliminary findings, foul play has been ruled out. The fire that engulfed the Victorian waterfront home was declared accidental. However, the investigation is ongoing.

The blaze tore through the $1.7 million home at 5 am on Christmas morning. Badger, a fashion advertising executive who works in New York, purchased the house in December 2010. Sometime after 3 am, Borcina removed the hot fireplace ashes and discarded them in a bag in the house's mudroom or a nearby trash container, Callahan said Tuesday.

Two hours later, firefighters arrived on the scene, where they found Ms. Badger on a second-floor scaffold. She directed the crew to the third floor where her children were sleeping, reports The New York Times.

The burning embers started the fire, which was so intense and hot that firefighters were pushed back when attempting to reach the other family members, Acting Fire Chief Antonio Conte told reporters. Once inside, they found the bodies of the grandmother and the three girls - a 10-year-old and 7-year-old twins.

The grandfather collapsed through the rafters outside a window. Here, crews found one of the girls, Conte said, indicating that he had been trying to get his granddaughter out. You have to realize with the amount of heat and smoke how scared those children must have been, Chief Conte said, and they just left him.

Johnson worked as a Santa at Saks Fifth Avenue in Manhattan and he and his wife were visiting Stamford to celebrate the holidays and their 49th wedding anniversary.

City officials said they plan to keep investigating the fire, but will need time. It's going to take a while, Conte said. That poor woman lost her entire family in one fell swoop.

We're still trying to put the pieces together, he said.

It is unclear whether the house had working smoke detectors or not, as it was undergoing construction. According to the home's building permit application, there were plans to install a new security and smoke detection system, Stamford Mayor Michael Pavia said, but it is unclear whether the working smoke detectors had been installed, reports CNN.

Mrs. Badger lost her three children and her two parents. When we made the initial contact with Mrs. Badger, the last thing on our minds to talk to her about was whether or not her building permit was valid or her smoke detector was working or any of that. ... As the follow-up investigation continues ... those are questions that we will pursue, but not now, he said.

The city of Stamford deemed the three-story structure unsafe and razed it on Monday.