DENVER—A local investigation into a deadly Colorado wildfire officially confirmed Thursday that it was caused by wind-blown embers from a prescribed burn set by the state forest service—but it found no criminal wrongdoing.
The Jefferson County sheriff’s office said Wednesday that the Colorado State Forest Service followed an approved plan for a controlled burn it conducted in the area March 22. It said wind-blown embers from the burn area ignited the Lower North Fork fire March 26. Three people were found dead in the fire zone in the Rocky Mountain foothills southwest of Denver.
The wildfire blackened 6 square miles and damaged or destroyed 23 residences before it was contained nearly a week later. The Jefferson County assessor’s office determined that losses at those residences exceeded $11 million, according to the sheriff’s report.
A separate review commissioned by Gov. John Hickenlooper said firefighters departed from their plan on one point by patrolling the perimeter of the prescribed burn for only two consecutive days after it was ignited.
The state-commissioned report was released Monday by William Bass, a veteran forest manager who led a team of specialists in examining only the controlled burn.
It concluded there was little firefighters could have done differently to prevent the disaster that followed the burn. Bass, a 37-year veteran of the U.S. Forest Service, said firefighters decided against going back as planned on the third day because they saw little risk.
The sheriff’s investigation said crews conducted mop-up operations at the prescribed burn site on March 22 and March 23, according to plan. They patrolled the burn perimeter March 24—again according to plan—and returned March 26 to monitor the burn and retrieve equipment, it said.
Bass said the wildfire showed that a 200-foot buffer—which he called standard practice—wasn’t enough for the high winds that raked the controlled burn March 26.
The sheriff’s office said it worked with the Bureau of Land Management and the U.S. Forest Service in its probe of the wildfire.
The Jefferson County coroner’s office is still working to determine the cause of the deaths. Authorities also are looking into problems with an automated phone call system that was intended to send evacuation messages to residents. Some people in the area did not get a call.
At a town hall meeting with residents Wednesday night, officials discussed a recommendation for a three-tiered evacuation alert system to better inform residents early on of potential dangers. The first tier would involve a warning that there could be an evacuation. The second would be a notice to prepare to evacuate. The third step would be an order to leave.
On March 26, after sparks from the prescribed burn jumped past the 200-foot buffer zone, firefighters discussed the potential need for evacuations if they couldn’t contain the flames quickly. However residents weren’t ordered to leave until more than two hours later.
