By Ed Fletcher, Sacramento Bee

In a scene that might have made Smokey Bear cringe, on a 100-degree day last July, a Sacramento man – in full view of his family and other witnesses – tossed a 2-inch diameter firework into a remote Placer County swimming hole.

An ember from the explosion shot 25 feet into the air, beyond a sheer rock face around the swimming hole on Shirttail Creek, and ignited the 2012 Robbers Fire, court documents show. The fire engulfed 2,630 acres, injured an inmate firefighter and destroyed four structures.

Bryon Craig Mason, 28, admitted to throwing the illegal firework, but his lawyer successfully argued during Mason’s preliminary hearing that Mason wasn’t guilty of arson because the fire wasn’t started willfully and maliciously.

The 2012 Robbers Fire in Placer County is a reminder how dry conditions can rapidly ignite. Photo/Randy Pench/AP

“There is no evidence to support the conclusion that a reasonable person would find it highly probable that the firework would explode in the water” clear a 25 feet high rock face and ignite a fire, said Placer Superior Court Judge Colleen Nichols in her ruling releasing Mason from custody earlier this month.

In her ruling, Nichols cited concerns about the credibility of the California Department of Forestry and Fire Prevention’s investigation of the fire.

The Placer County District Attorney’s Office has said it disagrees with the ruling but has not said whether it will make further efforts to prosecute the case. The District Attorney’s Office did not return calls for comment.

While prosecution of the incident may be in limbo, it does serve as a cautionary tale as fire season in Northern California approaches.

The region saw heavy precipitation early in the season but has been exceptionally dry since. Snowmelt is also ahead of schedule, pointing to an early start to fire season, said Tom Dang, a meteorologist with the National Weather Service.

“That basically prolongs the fire season for a month,” Dang said. “If we don’t see any precipitation between now and the end of the summer, fuels are going to be at exceptionally dry levels.”

He said the region may well see another storm before the end of May, but there are no significant storms on the immediate horizon.

Rui Cunha, assistant director of emergency services for Placer County, called for extra vigilance this summer.

“There is no question about it. The forest fuels are not getting the normal range of moisture. We are definitely going to feel the impact from that,” Cunha said. “It’s going to be even more important that we keep fire out of our forest land.”

Daniel Berlant, spokesman for CalFire, echoed the call for fire safety, saying: “We need to practice extra precaution.” He declined to talk about the case against Mason.

Placer County Supervisor Jim Holmes said the start of the Robbers Fire provides a fine example of why people shouldn’t play with matches. He said he could see how someone might think throwing fireworks into water was safe.

“I wouldn’t have done it, but I would have assumed it would be safe,” Holmes said. “It’s an unfortunate incident. I’m sure the gentleman had no malice. He wasn’t trying to set a fire. He was just trying to show off.”