ALBUQUERQUE, N.M. — Investigators have determined a wildfire that destroyed a dozen homes as it raced through part of the Manzano Mountains earlier this year started after a wood-chipping machine struck a rock and sent sparks flying into brush and forest debris.

It took just minutes for a small patch of flames to erupt into a blaze that would burn for weeks and end up costing more than $10 million to put out.

Details of the fire’s cause and the response by firefighters are outlined in a report released this week by forest officials.

The Dog Head Fire charred about 28 square miles after it started in June. Residents in several communities along the eastern side of the central New Mexico mountain range were forced to gather their belongings and round up their livestock before fleeing their homes as the fire ballooned.

The three-person crew that was using the machine to thin the area in hopes of preventing such a fire was armed with a shovel, an axe and one fire extinguisher. The report states the crew did not fight the flames because they were too intense.

The fire was reported to a supervisor and the crew moved their equipment further down the hill to a safer location. By then, the fire was moving along the forest floor and crowning in the tree tops.

There were no fire restrictions at the time of the incident given weather conditions and recent fire activity.

According to the report, officials called out two engines and aircraft to battle the flames from above. Two air tankers that had been ordered were put on hold as one official thought a helicopter would provide better support for crews on the ground. After a half-hour, it was learned the helicopter had yet to take off due to the startup process and safety checks so the air tankers were reordered.

More engine crews were called out and the battalion chief on the scene tried to establish an anchor point so arriving crews could flank the fire on the northern and southern sides.

“Fire behavior was intense in the heavy slash and forced ground resources to back out to a safe area until conditions moderated,” the report stated.

By the end of the first day, more than 100,000 gallons of fire retardant had been dropped around the perimeter by a fleet of several air tankers. The flames had burned just over one square mile and were reportedly cooling.

Things changed the following afternoon as the fire intensified and started its march toward the community of Chilili, forcing evacuations. Wind gusts into the night and favorable terrain helped the fire to grow.

It would be nearly a week before firefighters could stop the spread and it wasn’t until Sept. 12 that the fire was considered contained.

Forest officials said they are working with their partners to develop a complete assessment and identify what lessons can be learned. They have already pointed to the importance of communication among firefighters and law enforcement in different jurisdictions.

Rehabilitation of the burned areas is ongoing, and officials said the total cost of that work has yet to be calculated.