PALMER -- Authorities say a man and woman from Anchorage started the Willow-area Sockeye wildfire when they burned a pile of debris without clearing the area or having water on hand, allowing the fire to escape into a forest as they fled in their motor home.

They left behind a chain saw and gasoline cans in their haste, authorities said.

The fire destroyed 55 homes and heavily damaged 44 other structures, charring thousands of acres of forest within an 18-square-mile swath and killing numerous pets including some sled dogs in the community of about 2,000 residents known as Alaska's unofficial dog mushing capital.

The Palmer District Attorney filed criminal charges against 59-year-old Greg L. Imig and 42-year-old Amy K. DeWitt on Monday, according to a copy of the charging document.

Both are charged with second-degree criminally negligent burning and three counts of reckless endangerment, as well as failure to obtain a burn permit, burning without clearing the area, allowing the fire to spread, and leaving the fire unattended. All charges are misdemeanor offenses.

People responsible for starting a wildfire can be held accountable for up to twice the cost of fighting the fire, according to the Alaska Division of Forestry. At last report, the suppression costs related to the Sockeye fire were over $8 million.

Word of the charges -- and the cause -- floored at least some residents in Willow, where burned-out homeowners are just now starting to rebuild, many without insurance, a month after the fire began. Willow fire crews are still putting in 16-hour days chasing several hot spots.

Fire victims have been craving information about the cause, but some said finally hearing it Monday just made them angry and heartbroken.

Tamara and Gordon Boeve's home was spared but the fire destroyed nearly all the 40 acres of forest around it. Next door, a Willow firefighter lost his home and possessions, along with several dogs, while he evacuated dozens of people ahead of the fire, including one man who barely got out.

"All the pain these people caused. It's just so terrible," Boeve said in an email Monday after learning of the charges. "So many lives forever changed."

Both Imig and DeWitt are scheduled for arraignment in Palmer District Court July 28.

Imig appears to be the same Greg Imig who state records show is vice president and owner of a 20 percent stake in IMIG Audio/Visual Inc. of Anchorage, the main provider of technical services at the Dena'ina Civic and Convention Center, Egan Convention Center and Sullivan Arena.

The reckless endangerment counts reflect the "substantial risk of serious physical injury" to Willow and Houston residents, fire and emergency personnel, and residents whose homes were destroyed or damaged, the charging document says.

The fire started early in the afternoon June 14 at a cabin on a "well kept recreational property" with ample parking, manicured lawn and a camper trailer with separate yard deck, all owned by Imig and his brother on West Ringler Circle, according to an affidavit filed with the charges by Alaska Division of Forestry investigator Thomas Greiling. The property is just off West Sockeye Avenue and near Mile 77 of the Parks Highway north of Willow.

A flurry of 911 calls reported a rapidly spreading fire on Ringler Circle at 1:13 p.m., the affidavit said. It was hot and breezy: 83 degrees with winds of up to 10 mph blowing to the south.

Firefighters descended from Willow and other Matanuska-Susitna Borough stations as well as the Forestry Division in Palmer and Soldotna. Alaska State Troopers handled evacuations and traffic. First responders described a hellish, chaotic scene amid 100-foot walls of flame.

Forestry officials and the State Fire Marshal's Office conducted the investigation.

A resident across the street and a Willow Fire Department responder both told investigators the fire came off the Imig property, and aerial photos captured its start there and move into surrounding lands, the affidavit said.

The couple burned several piles of debris the day before the fire started and left them unattended that night, investigators said in the affadavit. DeWitt told them she put five boards atop one pile -- the one that spread into the woods -- because she thought if the boards began to burn, she could tell the fire was still hot.

She was working in the yard when unattended fire smoldering in the ashes crept into surrounding forest, according to the affidavit.

The couple located the debris piles right next to a thick spruce forest, with no evidence of a fire break to prevent the spread of flames, investigators found.

Numerous neighbors of the property reporting hearing fireworks the night before the fire started, then two loud booms in the afternoon before flames started torching through dry spruce, leading many to speculate that fireworks had been the cause of the blaze.

Investigators found evidence of both debris burning and fireworks, but could link only the debris to the wildland fire.

"Multiple items of spent fireworks were identified on this property, however conclusive evidence was not found that would indicate fireworks as a contributing factor to the cause of this fire," Greiling reported.

According to Forestry, Imig and DeWitt lacked a required permit for the burn and did not adhere to safe burning practices listed on such permits: the area around the debris pile was not cleared down to mineral soil; there was no hose or water source to prevent the fire from spreading into wildland; and the fire was left unattended.

Imig told investigators he didn't have a well or water hose and shouldn't have been burning given dry conditions and low humidity, the affidavit said. Both Imig and DeWitt admitted burning debris piles and not extinguishing them before leaving them unattended. They also told investigators they, with DeWitt's son, "rapidly exited" the property in a motor home due to the fire.

DeWitt said she called 911 but didn't provide the specific address or information about the fire's cause, according to the affidavit.

"Observations of the Ringler property indicated someone exited in rapid fashion leaving behind, and out in the open, items such as a chainsaw, gas cans and jack pads for a motorhome," Greiling said in the affadavit.

Imig and DeWitt were cooperative, Palmer District Attorney Roman Kalytiak noted in an email, "and there is no evidence that they intended to cause a huge forest fire. Hopefully the fire victims and public will understand that."

Forestry investigators and Kalytiak agreed "a thorough, but prompt, investigation and prosecutor review was necessary to protect the interests of all involved, to avoid speculation and to stress the importance of fire prevention given the past and current conditions," the district attorney said.

Even in the first days of the fire, it was clear the West Ringler recreational property was getting special attention. The Fire Marshal's Office and Forestry blocked it with survey tape and warning signs, asking even firefighters to steer clear in the interest of preserving evidence.

The reckless endangerment and negligent burning charges are misdemeanors punishable by up to one year in jail and a $10,000 fine while the other charges are lesser misdemeanors punishable by up to six months in jail and a fine up to $500, according to Forestry.

Willow fire chief Mahlon Greene said the one thing Monday's charges do is strengthen the argument for burn permits.