The key to identifying the cause of the still-raging Palisades Fire lies on a brush-covered hilltop where the blaze broke out just after 10:30 a.m. on Tuesday.

Fire investigators are still working to determine what sparked the inferno, but experts say it’s easy to rule out one common cause of wildfires: lightning. The region was free of stormy weather this week. The area near the Temescal Ridge Trail also appears to be free of power lines or transformers, which rules out another potential…