Millionaire Forrest Fenn's hidden treasure chest in the Rockies sparked a real-life treasure hunt, leading to obsession and tragedy. Five people died searching for the gold-filled chest whose location was hidden in a poem with cryptic clues. This full episode of 48 Hours investigates the captivating story of greed, mystery, and the ultimate price of obsession. "CBS Mornings" co-host Tony Dokoupil reports. #48Hours #FennTreasure #TrueCrime