A teenage boy was left facing a $15,000 dental bill after allegedly being punched at a Narrabundah party that spiralled out of control after it was advertised on social media.
Only 50 people were invited to the party at the Narrabundah community hall on Boolimba Crescent on Monday night, but more than 400 people turned up, according to police.
Police arrived at the party in force about 10pm, after they received reports of a fight.
The family of a 16-year-old boy, who was allegedly hit in the face, has contacted Fairfax Media, describing the behaviour at the party as ''disgusting''.
The teenager, who cannot be named, was at the party as an invited guest with his girlfriend, and was involved in a dispute with a gatecrasher.
He was allegedly punched, smashing out three teeth. His sister said he was still recovering from the attack on Tuesday morning, and was taken straight to hospital after the fight.
''He's very sore, I think he's just more in shock than anything,'' she said. ''He's such a gentle person and he didn't want to start anything … he's quite embarrassed, there was a lot of people there and people saw him.''
It took police several hours to shut down the party and move the crowd on, with one man arrested for intoxication and disorderly behaviour.
An ACT Policing spokesman said they had received reports of an assault, and were still investigating the allegations.
The nearby Narrabundah newsagency was hit by vandals on Monday night, but it is unclear whether it is linked to the party.
Residents reported seeing hundreds of teenagers flood out onto the street, disrupting the usually quiet neighbourhood.
Jane Camilleri, who has lived on Boolimba Street for 53 years, said the noise coming from the group had scared her.
''It was very noisy, very, very noisy,'' Mrs Camilleri said. ''I was scared because I thought there might be fighting … all I could see was a fire engine there and then I saw the police.
''I thought, this is not going to be like Sydney, is it?''
Other residents said the young people were loud but well behaved.
Alberto Scuderi, who lives opposite the community hall, said he went outside to watch the scene unfold.
He said he feared the party might get out of control, but said the police arrived early and subdued the crowd.
''I said, 'we're going to have trouble here tonight once they start drinking','' Mr Scuderi said.
''I've never seen so many people come out of that hall,.''
Another resident said three cars, containing about 10 young people, had pulled up outside their house about 10pm.
The resident said he questioned the group, and they told him they were waiting for the police to leave so they could go back to the party.
''One of them tried to relieve himself in our driveway,'' he said.
''They left fairly promptly when I threatened to call the police.''
Narrabundah Newsagency owner Barry Thomas said a lotto sign outside his shop was vandalised on Monday night, and a small wooden counter, used to fill out lotto tickets, was also damaged.
It was the first time the newsagent had been vandalised since he took over as owner in November.
Officer-in-Charge of Woden Police Station Sergeant Steve Hogarth said the party lacked ''a responsible host'' and had to be stopped.
''Attending officers estimate that more than 400 people attended the party, much more than the 50 invited guests. A large percentage of the 400 people were under the age of 18 and affected by alcohol.''