Investigators were at the scene of a house fire Monday to determine how the crawl space of a 4,000-square-foot house caught fire Sunday night.

Kirkland Firefighters quickly responded to a home located at the 5700 block of 125 Ln. N.E. in the Bridle Trails neighborhood at around 5:15 p.m.

Acting Battalion Chief Kenneth Henderson said the house is “probably not” livable.

“(It’s ) due to the fact that there was enough fire damage under the flooring that could have damaged the electrical or gas, which has been shut down,” Henderson said.

Firefighters had to cut several areas of flooring to get to the crawl space where the appliance fire was contained.

The family of four did not sustain injuries and neither did their fish.

Henderson said one of the occupants of the house had a saltwater fish tank that needed a generator. So, one of the crew members was able to accommodate them until the owner could find an alternative solution.

“They’re expensive fish,” Henderson said.

Two ladder trucks, two battalion chiefs, four fire engine trucks, an aid unit and two other fire units responded with help from the Bellevue and Redmond fire departments.