In April 1896, Athens, Greece, hosted the first Olympic Games of the modern era. And nearly lost everything in the process. The country was already bankrupt when it took on the competition, but the relatively new royal family believed the games would boost its popularity. (The Greek royal family was actually from Denmark).
Kicking off an Olympic tradition, organizers grossly underestimated the cost of hosting the games. The perceived cost of 585,000 drachmas (about $74,000 in 1896) to prepare for the competition ballooned to 3,740,000 drachmas, the equivalent of $448,000. Much of the overage was attributed to the expense of restoring Athens' ancient stadium [source: Jennings, Zarnowski].
Fortunately, a 1 million drachma donation from a rich businessman helped underwrite the costs. And as the games got underway, bustling sales of souvenir stamps and medals brought in additional revenue [source: Jennings, Zarnowski]. Crisis averted.