A fire that severely damaged all businesses at the Plum Tree Plaza in Edmonds early Saturday morning is now being investigated as an arson. Crews were called to the plaza on Saturday just after 5:30 a.m. after getting reports of flames coming from a business within the small complex at 22315 Highway 99. About 75 firefighters from several agencies were at the scene as well as multiple area law enforcement personnel. Evidence from the scene appeared to show that the blaze started in one specific business, but multiple units were destroyed. All 14 businesses were damaged from either the fire or water of putting the flames out. Investigators say evidence shows the fire was set intentionally. Edmonds police detectives are continuing to work with agents from the Bureau of Alcohol Tobacco and Firearms (ATF) on the investigation to include collecting surveillance footage from area locations.