A Federal Way house that caught fire Thursday evening is suspected to be the site of an illegal marijuana grow operation.

South King Fire and Rescue crews, along with Valley Regional Fire Authority and King County Medic One, responded to the residential fire around 4:15 p.m. on Nov. 21.

Crews made an aggressive interior attack to contain the house fire, located at the 2000 block of S. 312th St., according to SKFR Assistant Chief of Operations Kevin Crossen. On scene, Chief Vic Pennington declined to comment.

Firefighters worked to ventilate the roof of the house, then gained entry through an attic window on the south side of the house. After conducting rescue searches, crews found no occupants in the house, Crossen said.

Federal Way police officers responded to the scene around 4:20 p.m.

“It quickly became evident this residence was the location of an illegal marijuana grow operation,” noted Cmdr. Kurt Schwan of Federal Way police. “It was determined the fire was most likely caused by a space heater.”

After being made safe by fire personnel, Special Investigation Unit detectives responded to assume responsibility for the investigation, Schwan told the Mirror in an email.

Items of evidence were recovered from the residence, but no suspects were located, he added.

The Mirror will update this story as more information becomes available.