OAK HARBOR, Wash. – A 25-year-old mother and her two children, 3 and 5 years old, died in a house fire Sunday.

At around 4:30 p.m. Sunday, a neighbor called 911 to report the fire. As crews were working to extinguish the flames, the husband/father drove up to the scene. He told police he had been shopping at Costco the whole time. He was cooperating with the investigation.

Authorities say they hope the situation is nothing more than a horrible tragedy, but at this point they just don't know. Arson investigators and analysts from the State Patrol crime lab spent all day Tuesday going over the scene in the 4100 block of DeGraff on the north end of Whidbey Island.

Police say at this point they have no reason to believe there is any foul play involved. Neighbor Joe Crollard, who lives behind the family says things just don't add up.

"It's a one story house with big windows. All you'd have to do is break out a window. It's a 4-foot drop for the kids and everyone is out," he says. "Something is wrong."

Autopsies will soon be performed on the three victims. Police say the husband/father is in the Navy and is stationed at NAS Whidbey Island. He is reportedly staying with friends or family right now.