The Beechcraft Baron took off through the slanting afternoon sunlight, its twin props whipping the thick summer air as the small plane gained altitude over the Caribbean Sea. On board, the two couples were traveling light, just day packs and a styrofoam cooler. They had spent the afternoon exploring the Mayan ruins at Lamanai outside Belize City and were headed back to their hotel near the island village of San Pedro 40 miles up the coast.

At the controls was William Fincher, a millionaire real estate developer from Houston, who was ferrying his new fianc�e and another couple on a weeklong excursion around the tropics. Even to those who knew him well, Fincher remained an almost mythic figure: a decorated combat Marine in Vietnam; fourth-degree karate black belt; competitive weight lifter; crack pilot; skydiver; scuba diver; mountain climber. At 50, Fincher had survived so many harrowing adventures that friends considered him all but indestructible.