Nobody was injured in an early morning house fire in Oak Harbor Saturday, but the blaze displaced a family, according to the Oak Harbor Fire Department.

Chief Ray Merrill said neighbors of the house on Southwest Third Avenue heard a crashing sound and looked outside to see flames shooting out of the back of the house at about 4:40 a.m. They called 911.

The family was not home at the time of the fire.

Firefighters with Oak Harbor, North Whidbey Fire and Rescue and the Navy responded, with the first units arriving within four minutes of the call. But they found the fire was already consuming the two-story, 1,600-square-foot house.

Merrill said it took firefighters about 30 minutes to get the fire under control but about two hours putting out all the hot spots. The conflagration caused extensive damage to the structure.

“It’s pretty well destroyed,” Merrill said.

The chief said the cause of the fire is a bit of a mystery but seemed to have started in the kitchen, though it doesn’t appear to be stove or cooking-related. The investigation into its cause is continuing this week, he said.

The fire department again reminds people about the importance of closing interior doors in a house. The slogan is “Close when you doze,” but Merrill said it’s also a good idea to close doors to rooms when no one is inside.

In the recent fire, doors were closed in two rooms on the first story, and the interiors sustained minimal damage. Everywhere else, Merrill said, the damage was extensive.

“It does make a big difference,” he said.

• For more information about how to keep families safe in case of an emergency, check out the fire department’s Facebook page and twitter feed at twitter.com/OakHarborFD.