FBI analysis details final hours of family who died on remote Northern California trail

It was high summer, and temperatures were climbing swiftly on a remote trail in the Sierra Nevada near the small community of Mariposa.

Jonathan Gerrish and his wife, Ellen Chung, knew they were in trouble.

Out of water, exposed and overheating, they had to ascend the rugged and steep Savage Lundy Trail to return to their vehicle at the Hite Cove trailhead. Their 1-year-old daughter, Aurelia "Miju" Chung-Gerrish, and dog, Oski, were with them.