A cowboy rides through a pen with cattle in Chihuahua, Feb. 17, 2012. Reuters

A girl's birthday party in Mexico that was attended by thousands of people after the video invitation to "everyone" went viral on social media left one person dead. A man was killed Monday after he stepped into the path of a galloping horse during a race in honor of the girl's birthday, BBC reported.

"Hello, how are you? We invite you this 26 December to the 15th birthday party of our daughter, Rubi Ibarra Garcia," Crescencio Ibarra, the father of the teenager, said in the video while standing next to Rubi and his wife Anaelda Garcia.

Weeks before the party, Ibarra created a Facebook event and video that was originally intended specifically for the family’s neighbors and friends. However, he didn’t realize that the invite was set to “public” instead of “private,” People reported. The invite went viral, with 1.2 million RSVPs, 978,000 shares and #XVdeRuby trending on social media.

In the video, Ibarra announced that the winner of the horse race to be held as part of the event would win 10,000 pesos ($490).

Another man, who also stepped into the path of the horses, broke a leg, according to local police, who also said that apart from the accident during the horse race, the party went off peacefully.

On Monday, Rubi took to Facebook to speak to all those who attended the party.

“To all those who have already arrived I ask you to please do not despair because in truth we are many people and we are just seeing how to speed things up,” the girl wrote. “I just ask for your patience so that we can all enjoy this party.”