Around 1600 people were cleared from the streets of a quiet Hamburg neighborhood on Friday, June 3, after police had cordoned off a house where a 16-year-old German girl had wanted to celebrate her birthday with family and friends.
The revelers outside - carrying posters saying "We love Thessa" - were celebrating the birthday, too, though they hadn't been invited - at least not intentionally.
The 16-year-old had posted an invitation to the party on the social networking site, Facebook, and accidentally listed the party as a public event.
After over 15,000 people responded confirming that they would attend the party, the 16-year-old attempted to correct the mistake by cancelling the party over the site. The cancellation was to no avail, however, and by early evening hundreds of young Germans from Hamburg and across Germany had already begun arriving.
"It was a great party atmosphere," said one visitor, Angelika. "It's almost like a festival here."
Police broke up the party at 1:55 am on Saturday morning. More than 100 officers were at the scene. Six revelers were arrested on suspicion of aggravated battery and property damage, but they have since been released.
Thessa opted to celebrate her birthday elsewhere.
Police said some people were injured after they stepped on pieces of broken glass. "Multiple units" were stationed outside the family's house, a spokesman said, and several streets were closed off. The family also hired a private security company.
As the evening wore on, there were isolated incidents of bottles and firecrackers being thrown toward the police.
"There were stones, bottles and fireworks flying, and party guests took apart (people's) front gardens," Streiber said. "Fences were trampled."