Sept. 6, 2003 -- Jean Ann Cone and Hillary Carlson were two women with a great deal in common.
Both resided in Tampa, Fla. Both sent their children to Berkeley Academy, a prestigious prep school. Both had facilities at Berkeley named in their honor — The Jean Ann Cone Library and Carlson Field. Both served at the same time on a school board of trustees. Both drove pricey Rolls Royces.
But this spring, Tampa society was shocked to learn the two women had far more in common than fancy cars: For decades, both had lived with the same man and called him the father of their children.
It turned out 74-year-old Tampa millionaire Douglas Cone, husband of Jean Ann, was also Don Carlson, husband of Hillary.
"He was using an alias, Don Carlson, as the prop in a double life that he had been carrying on for more than 20 years," said Christopher Goffard of the St. Petersburg Times.
Cone may have been able to fool so many people for so long because he told each spouse he had to go away a great deal on business.
Secret Came Out in March
The secret life of Douglas Cone began to unravel in March when his original wife of 51 years died. Jean Ann Cone had been at a party and, after driving herself home alone, fell asleep in the couple's garage before turning off the car.
"The cause of death was carbon monoxide poisoning," said Tampa police Sgt. Jim Simonson. "It's obvious that she had some kind of a medical situation where she just passed out, and then that's the way she died."
Tampa police ruled the death an accident.
But the community was set abuzz two weeks later when Douglas Cone married Hillary Carlson — the woman he had shared his secret life with.
Among those stunned was Panky Snow, who grew up with Jean Ann and was a bridesmaid in the young cheerleader-turned-socialite's wedding.
"I had no reason to suspect anything," she said. "I loved Doug. He was very sweet and kind and nice. And I still am a little in shock about what happened because I can't believe he would do that to her."
Secluded Secret Life
Cone's remarriage was a legalization of a relationship he'd secretly maintained for years in a secluded Tampa manor. There, as Don Carlson, Cone managed to keep his second family hidden from friends — even, it seems, from Jean Ann, who continued to share a home with him a mere 20 miles away.
"I don't see how Hillary could not have known," Goffard said. "Whether Jean Ann knew is another question. Some of her friends think that she was too proud a woman to have permitted such a thing to happen."
Neither of Cone's two children from his relationship with Hillary Carlson, nor at least two of Cone's three children with Jean Ann, knew about their father's secret life.
Cone/Carlson has not been speaking with the media.
The two Tampa families haven't officially met, but there have been multiple brushes. One of Cone's granddaughters from his marriage to Jean Ann was in the same high school class as a daughter from his relationship with Hillary. Neither knew they were related.
Complicating matters for both families was Doug's reported battle with lung cancer.
Many in Tampa wonder how the millions made by the construction magnate responsible for some of Florida's biggest roadways will ultimately be divided or fought over.
As for old friends, most aren't sure what they'll say to Cone, should he resurface on the causeways and waterways of upscale Tampa, but a few have some ideas.
"How could you?" Snow said she would tell him. "How could you?"
ABCNEWS' Robin Roberts contributed to this report.