Pacific Gas and Electric Co. power lines coming into contact with a tree may have sparked the Butte Fire, which has killed two people and scorched more than 70,000 acres in the Sierra foothills, a company spokesman said Wednesday.

“While we don’t have all the facts yet, a live tree may have contacted a PG&E line in the vicinity of the ignition point,” Barry Anderson, PG&E vice president of emergency preparedness and operations, said Wednesday. “We are cooperating fully with Cal Fire in an investigation of whether this could have been a source of ignition for the Butte Fire.”

As part of the probe, “we are reviewing our inspection and patrol data for 2014 and 2015 for the area near this tree and we will be sharing the results of those inspections and patrols” with the state Department of Forestry and Fire Protection, Anderson said.

The fire started Sept. 9 east of Jackson (Amador County). It has burned 71,780 acres in Amador and Calaveras counties and is 45 percent contained, Cal Fire said.

Two men have died in the fire, both of whom remained in their homes despite evacuation orders, officials said.

Mark McCloud, 67, was found near his home on Baker Riley Road near Mokelumne Hill (Calaveras County). The other victim died in his home nearby, said county Coroner Kevin Raggio. He identified the victim only as an elderly man.

“I’ve never seen anything like it,” Raggio said of the fire’s destruction. “In such a small county like this, it just brings a tear to your eye.”

This wouldn’t be the first time a PG&E line sparked a wildfire. In 1997, PG&E was found guilty of 739 counts of negligence for a pattern of tree-trimming violations that led to a devastating 1994 wildfire in the Sierra.

The fire destroyed 12 homes near the Gold Rush town of Rough and Ready. PG&E was fined $1.6 million for the violations.

Anderson said PG&E has been stepping up its efforts this summer to prevent fires.

“Since June, we have been conducting daily air patrols along sections of major electric lines to look for hazards that could spark wildfires,” he said in a statement. “We have provided $2 million in funding to local fire safe councils for fire fuel reduction, emergency access projects and public education. We have provided funding for lookout towers and cameras for early fire detection.”

Kale Williams is a San Francisco Chronicle staff writer. E-mail: kwilliams@sfchronicle.com Twitter: @sfkale