A case of fast money and even faster living.

A life of private jets and black-tie balls ended with Seth Tobias, a wealthy investment manager and a familiar face on CNBC, floating face down in the swimming pool of his mansion here. It was just after midnight on Sept. 4 when Tobias's wife, Filomena, frantically called 911, the emergency telephone number. "Please send somebody, please!" she screamed. "He's not breathing!" By the time the police arrived, she had pulled her husband's body to the edge of the pool, where she cradled his head in...