The Sky is Falling by Sidney Sheldon

The Winthrops are America's royal family, and its Prince Charming is the sexy, charismatic Gary Winthrop. Now the man on his way to becoming the Senate's brightest new star is found murdered in his home—the latest in a series of accidents that have killed five members of the family in a single year. One of the last people to see Gary Winthrop alive is Washington anchorwoman Dana Evans. She makes it her mission to investigate these seemingly random tragedies, little realizing that her search will sweep her across several continents, place her and her young son in grave danger, and lead her to a truth that will astound the world.