SAN MARCOS, Calif. - Residents of the Coronado Hills community in San Marcos are questioning how the Cocos Fire started.
"It's suspicious to me," one resident said.
A man who did not want to be identified told 10News neighbors who live where the fire burned believe the cause is suspicious.
"There were some vehicles seen up in the area here," he said.
Neighbors say there are cameras at a business down the hillside that are being looked at and that someone reported seeing more than one car on Cocos Drive Wednesday afternoon before the fire started.
"There were a number of people in that area in that vicinity seen on Cocos, more than one person," he said.
10News viewer Brian Walker sent in cellphone video he took of what appears to be the start of the fire.
Walker was standing on the roof of a business about one and a half miles to the north. He says he was too far away to notice anything suspicious.
"It went to the right, and it just started burning up that hillside up toward the other homes with the trees behind them," he said.
Based on the video, a 10News crew took the camera to where it appears the fire started but there was no clear sign of an ignition point. All that can be seen is burned brush in between the homes, which are spread out.
10News shared the video with Cal Fire to get some insight.
"It was burning in steep terrain in thick vegetation," said Cal Fire Capt. Kendal Bortisser.
A Cal Fire spokesperson says it is too early to tell the cause but videos like that one could hold the key to determining if it was intentional or accidental.
"That could potentially be the one piece of evidence they need that could determine the cause. It could determine the location of the fire," Bortisser said.