MARYSVILLE — A 13-year-old Marysville boy has admitted to setting the July 23 Welco Lumber yard fire, according to a statement issued by Marysville Police Cmdr. Robb Lamoureux.

On the day of the fire, witnesses told Marysville Police they’d seen a group of juveniles in the area just prior to the fire starting.

On the evening of July 26, the boy’s parents brought him to the Marysville Police Department, where he admitted to police officers that he was responsible for the fire at 1218 First Street in Marysville.

Three other Marysville boys, all 13, have also been identified as being with the suspect at the time of the fire, but are being treated as witnesses.

The boy has been released into the custody of his parents. Arson investigators will file the case with the Snohomish County Prosecutors Office early in the week of Aug. 3.

Damages to the building, whose roof collapsed as a result of the fire, are estimated at $100,000, but there are no plans to rebuild at the site. The cost of cleaning up the site is estimated to be $15,000.

The mill was vacant and no injuries were reported, but according to officials, squatters and transients have been a problem in that area. As many as 50 firefighters from neighboring districts assisted the Marysville Fire District, including Tulalip Bay, Everett, Getchell, Lake Stevens and Stanwood.