Early on the evening of Jan. 7, a resident of a neighborhood of homes backed up against the San Gabriel Mountains in Southern California saw what he described as a bright white light, and then a small fire at the base of an electrical tower up in Eaton Canyon. Another neighbor reported that his lights flickered a few minutes before he saw fire underneath the tower.

So far, many clues to the origins of the deadly Eaton fire, which started in the area just after 6 p.m. that evening and went on to kill 17 people, have pointed to the brushy hillside where a tangle of electrical lines stretch up Eaton Canyon.

Yet Southern California Edison, the utility that operates the electricity infrastructure in much of the Los Angeles region, has said it has no record of an electrical failure on its lines in the vicinity, and that three low-voltage distribution lines in the area had been de-energized long before the fire.

While an official cause is likely to take months for investigators to determine, a growing body of evidence is emerging that suggests the fire started in the dry grasses below a set of transmission towers carrying high-energy power lines. The lines were buffeted that evening by winds that at times reached 100 miles per hour.

A new video, recorded by a surveillance camera at a gas station less than a mile south of the towers, appears to provide an important new clue: Supporting what the residents saw, it shows flashes of light at 6:11 p.m. in the vicinity of three high-voltage electrical towers in Eaton Canyon, and then flames moments later.