Last February, Hugh Hefner and his posse held a fundraising event at the notorious Playboy mansion. And as you probably have already heard, over 100 of the guests reported having pneumonia and flu-like symptoms after the evening's shindig came to a close. What caused this? The LA Health officials finally have the answer.

Two months later, Los Angeles Health officials finally know what may have caused the outbreak: the Legionella bacterium, a potentially lethal bacteria that causes Legionnaires' disease. It was located in a sample of water taken from the Playboy's famed hot tub.

Health officials will continue looking for other possible causes of the outbreak until they know for sure what caused it. It's possible that the H1N1 virus or influenza is to blame, as well.