A Cal Fire hand crewman limbed the branches off a 68 foot, 11,040 pound Ponderosa pine less than 20 minutes before it rolled down a hillside, killing a Calaveras County roads maintenance worker, but investigators did not determine that was what caused the log to move, a Cal Fire accident investigation report said.

Ansel John Bowman, 57, a more than 10-year county employee, was crushed by the log while assisting a crew near a wood chipper on the 8300 block of Doster Road near West Murray Creek Road on March 18.

Michael Mohler, a deputy director with Cal Fire in Sacramento, said it was too early to determine if any person or agency was culpable.

“Obviously something happened up there, which dislodged the log. I can't say by reading this report what it was,” Mohler said. “We will not leave any stone unturned in this investigation.”

The accident investigation report, known as a Green Sheet, said an inmate from a Cal Fire work crew was removing branches from the log — believed to be downed in fall 2018 and located on a hillside, parallel to Doster Road and near Mountain Ranch in the Butte Fire burn scar — after 9:54 a.m.

At 10:16 a.m., a member of the crew “heard a very loud snap” near the log. He yelled out loud, “Rolling downhill!” Rolling downhill” and the workers scattered.

Within seconds, the log rolled down onto the single-lane, 12-foot-wide Doster Road. The stump side hit Bowman, who had put up his left arm to brace for the impact. The log also hit a crew member in the back who was feeding a woodchipper attached to a truck. The crew member, who was unable to hear the shouts because of earplugs, sustained minor injuries.

Calaveras County Deputy Keith Rosa with the coroner’s office said Bowman’s official cause of death was multiple blunt force injuries due to a rollover by a large tree.

“It’s an active dangerous scene. We have some of the best policies and procedures in place, but we can’t prevent every accident or injury,” Mohler said.

Mohler said Cal Fire did not down the tree. Mohler said the style of cut at the stump was not authorized by Cal Fire policy and there were no records indicating crews had done previous work in that area.

Joshua Pack, Calaveras County director of Public Works and Transportation, said in an email the county was conducting an investigation into the death, but there was no time frame for its completion.

“It is my intention that we will release a response to the green sheet finding at that time. We also recognize the need to complete an investigation in a timely manner while respecting the investigation process,” he said in an email.

Pack also said the county did not know who felled the tree.

“We can verify that the log in question was not felled by county forces or by contractors performing work on behalf of the county,” he said.

The crews were cutting and chipping tree limbs and processing other woody debris impacted by winter storms.

According to the Green Sheet, the Cal Fire worker removed branches from the top of the tree toward the stump on the uphill side of the log. On the way back along the downhill edge, he removed from the stump to the top.

The slope of the hill from the approximate centerpoint of the log varied from almost flat (18 percent) to very steep (115 percent). The log was located at a slope of approximately 54 percent, above a 73 percent grade at the centerpoint, with the top end located on a flat surface with a zero percent grade. The log was 30.5 inches in diameter and rolled 37 feet 8 inches down the hill, the report said.

The document said the worker noticed many branches lodged into the soil underneath the log. Those were not removed, but the tree appeared to “settle” when a long branch on the downhill and top side of the tree was removed.

When the work was completed on the log, the worker proceeded with saw operations near the area before the log rolled down the hill.

There were 14 handcrew members, a Cal Fire Fire captain, and two Calaveras County road maintenance workers at the site. The accident was investigated by the Cal Fire Serious Action Review Team (SART), which utilized light detection and ranging (LIDAR) technology to measure times, distance, space and elevation.

Pack said his office was still grieving over the loss of a friend, associate and coworker.

“Words alone cannot express how much John’s passing has affected each and every one of us,” he said.

Both Pack and Mohler said the accident provided both groups an opportunity to take stock of safety procedures at work sites.

“We must continue our efforts to provide our crews with the proper equipment, training, to ensure we minimize the risk for future incidents like this,” Pack said.

Frank Polizzi with the California Occupational Safety and Health Administration said the inspection of the Calaveras County Public Works project remained an open investigation.

Contact Giuseppe Ricapito at (209) 588-4526 or gricapito@uniondemocrat.com . Follow him on Twitter @gsepinsonora.