The Longman Dictionary defines fortuitous as “happening by chance, especially in a way that has a good result.” The author suggests that this distinction is a loss to the language when the words are blurred. The word fortunate has been used in recent years to express a range of meaning. The main sense of fortune for centuries was "accident," but by the fifteenth century it could also mean “good fortune” and soon it specialized to “prosperity” or “wealth,” as in “He made his fortune’s fortune. English fortunate always meant “with good fortune  or ‘favored by fortune“, but the noun fortune by itself is not always favorable or good. The article suggests that while fortune is often referred to as "random," or "fantuitous," it is also a sign that luck is a good thing.