Law enforcement officials are confirming that a massive fire at a Gilbert construction site on Saturday was intentionally set.
Law enforcement sources said Thursday that they are continuing to investigate the case of arson.
It took 150 firefighters to put out the fire, which completely destroyed an apartment complex under construction near Gilbert and Guadalupe roads.
Footage from the scene showed the site had become an inferno, with smoke and flames visible for miles.
Crews from the Chandler and Mesa fire departments also responded to assist.
Firefighters say flames tore through eight buildings and melted playground equipment, but fortunately, no injuries were reported.
Damage is estimated at $10 million.
Witnesses told authorities that a man, between 16 and 22 years old, was spotted in the area wearing a maroon Arizona State University sweatshirt and dark-colored shorts.
Fire officials are hoping to speak with him for additional information regarding the blaze. He was wearing long socks and Vans-like shoes. He had shaggy brown hair to the bottom of his ears, long bangs and no facial hair.
Gilbert Police and Fire Departments are offering a $30,000 reward for information leading to the arrest of the person, or persons, responsible.