Melted remains of an old car tire. Two burned trees. A stump of an abandoned utility pole. These are among the pieces of evidence investigators are examining as they seek to solve the mystery of last month’s Maui wildfire: How did a small fire sparked by downed power lines and declared extinguished flare up again hours later into a devastating inferno? The answer may lie in an overgrown gully beneath Hawaiian Electric Co. power lines and something that harbored smoldering embers from the first fire and rekindled into a wall of flame that destroyed the town of Lahaina and killed at least ...