Fire officials determined after their daylong investigation that the blaze was started accidentally by a burning candle at the center of the memorial structure.
Central Fire Authority Fire Chief Doug Williams, who oversaw the investigation, said no evidence of accelerants, such as gasoline, was found at the site.
Williams could only speculate that the candle was somehow knocked over, perhaps by a gust of wind. "It's an open flame is what it amounts to," he said.
Andy Lopez Memorial Site
Seven arson investigators from four agencies -#8212; Cal Fire, Sonoma County Fire, Central Fire and Rincon Valley Fire -#8212; examined evidence at the scene Thursday. The number was unusual for a fire of a such a small size and reflected the sensitive nature of the memorial site.
"There's a lot of meaning attached to it. We wanted to be sensitive to that," Williams said.
Lopez was shot Oct. 22 by Deputy Erick Gelhaus as the boy walked through his southwest Santa Rosa neighborhood carrying an airsoft BB gun designed to resemble an assault rifle. Gelhaus told investigators he thought the boy was carrying an AK-47.
Within days, those both mourning Lopez and protesting his death built a 19-foot-long wooden shrine in a vacant lot at the site of the shooting. The memorial, which was decorated with candles and flowers, resembled a type of grave marker common in Mexico.
Caretakers of the site said electricity had been cut off for about a month from the strings of lights that hung around the tent and altar, only because a neighbor could not keep pace with the electricity bills.
Further, they said, candles that once burned at all hours had been limited to a few prayer candles positioned near the sidewalk -#8212; about 20 feet from where the altar burned.
Regular visitors to the site said several photos of Lopez were missing after the blaze, further fanning their suspicions that it was arson.