The mother of all sweet sixteen parties was marked by dozens of injuries, two fires and an injured police officer when more than 1,500 guests turned out for an unintentionally massive party for a teen girl in Germany.

The result was "sheer insanity" and a lesson in the importance of Facebook's privacy settings.

The birthday girl, identified only as Thessa, forgot to flag the invitation to her party as private. Open to everyone on the social media site, the invitation went viral and some 15,000 strangers from all over the world clicked that they would attend the shindig in Hamburg.

About 1,500 teens and young adults turned up, filling the street outside Thessa's house, but there was not enough cake and pop for all.

The family cancelled the party, informed the police and hired a private security service to protect their home.

"We had cordoned off the house, some 100 police were on the ground, four of them on horses -- but that did not keep the kids from celebrating," police spokesperson Mirko Streiber said Sunday.

Some held up signs asking "Where is Thessa?" Others brought birthday presents, homemade cake and copious amounts of alcohol.

Streiber described the party as "a hit" adding that it was, "sheer insanity but mostly peaceful."

Eleven people were temporarily detained, dozens of girls wearing flip-flops cut their feet on broken glass and one police officer was injured when he tried to stop a party-goer from breaking the Mercedes-Benz logo off of his patrol car. Firefighters put out two small fires.

Thessa, who had planned to mark her 16th birthday with a small group of friends, fled the scene and reportedly celebrated "at an undisclosed location" with her family.

With files from The Associated Press