SIGNAL MOUNTAIN, HAMILTON COUNTY (Times Free Press)-- Just 23 minutes after dropping off her two young children, Gail Palmgren drove along East Brow Road in her 2010 crimson Jeep Rubicon.

The sun was shining and the skies were clear on April 30 as the vehicle went off the road onto a small grassy area and struck a tire-size boulder weighing about 435 pounds. The Jeep went airborne and overturned, the rear crashing on one bluff, then another, falling a total of about 350 feet. The vehicle lay in a wooded area at the base of Walden's Ridge above the W Road for about seven months before it was discovered.

Now Hamilton County Sheriff's Office investigators have examined the Jeep wreckage and used the vehicle's black box to try to learn why Palmgren, 43, drove over the edge.

Investigators said Palmgren was not wearing her seat belt when the Jeep crashed. They have declined so far to release other findings from the box.

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