A mother and her two young children perished in a deadly house fire on North Whidbey Sunday.

The victims have been identified as Laura White, 25, Ivylynn White, 5, and Imriel White, 3. Island County Sheriff Mark Brown said a cause has not yet been determined, but that the investigation is ongoing and that detectives are looking into the possibility of foul play.

“At this time we have no hard evidence of criminal behavior being involved, but are not ruling it out as a possibility,” Brown said.

Police say the woman’s husband was not home at the time. He arrived as firefighters were putting out the flames. He has not been named as a suspect and is cooperating with authorities, Brown said.

Department spokesman Detective Ed Wallace said early Monday that investigators and forensic crime lab units were processing the scene for any evidence of criminal wrongdoing.

The fire was reported at about 4:30 p.m. on the 4000 block of DeGraff Road. North Whidbey Fire Chief Mike Brown said it took fire crews from multiple agencies about 45 minutes to knock the fire down.

David Hamilton, a neighbor and eyewitness to the fire, said he and his wife started seeing smoke from their backyard about an hour before he heard sirens. They live about 100 yards away and their backyard abuts with the charred remains of the home, only separated by a few trees.

“We just thought our neighbor was burning garbage at first,” Hamilton said. When he finally saw the flames rising above the trees, he immediately dropped what he was doing to run over to the house.

“I dropped my chainsaw and ran over to see if I could help, but the house was already engulfed in flames,” he said.

As Hamilton watched, he said he never heard any yelling from the house and was unaware at the time that victims were inside.

Brown said White’s body was recovered Sunday night, but the two children were not recovered until Monday. Brown said autopsies will most likely be performed on all three victims.

“I have extreme admiration for our first responders, but one in particular who I think is often overlooked is the Island County Coroner Robert Bishop,” Brown said.

He said that Bishop in the last two weeks has had to recover small children from two different fire scenes. The last one being a car fire on Camano Island, Brown said.

Brown said the sheriff’s office will announce any significant developments in the case on its website.

Michael Watkins / Whidbey News Group A residential structure fire broke out Sunday Dec. 18, 2016, in north Whidbey Island killing a 25- year-old mother and her two children ages five and three. Investigators are still determining the cause of the fire.