The incident has highlighted the horrifying consequences of having a teenage house party.

It doesn't mean parents need to shy away from a party, but they need to be aware that hundreds of people can hear about a party in just minutes.

'In the past seven to 10 years, communication has become very different,' says former police officer Mark Ellis from Gatecrash Security in Brisbane.

'This kid is talking about his success as a party promoter. But basically, anyone can get people to a party - all you need to do is post it on MySpace or Facebook. SMS and email are other ways kids can tell friends about an event. They just have to send one message to their phone book and before you know it everyone turns up.'

The key to hosting a successful teenage event is through careful planning. It's worth checking with the police in your state for advice on hosting a safe party. The NSW Police Force has valuable advice for parents - visit www.police.nsw.gov.au 
to download your Safe Party Pack.

Mark explains that many gatecrashers aren't there to cause damage or be violent. Most just want something to do. But when you add drugs and alcohol, the behaviour can turn rowdy.

If gatecrashers do turn up, the key is to stop them early. As is all too common, by the time the police arrive, the situation is out of control.

'Most parties are held on Friday and Saturday nights, which are busy times for police, and if you do leave it solely in their hands, by the time they arrive it's too late,' Mark says.

But this wouldn't have made a difference in Corey's case because his parents had no idea there was a party taking place at all, which raises the issue of parental responsibility.

'It's one thing to talk about Corey Delaney's parents, but let's remember there were also 499 other teenagers whose parents weren't aware of their children's whereabouts,' psychologist Andrew Fuller says.

'It's easy to point the finger at the guy who hosted the party, but where did the parents of all the other kids think they were?'

What happened in Melbourne only highlights the fact that parents of teenagers need to know what they're doing and where they're doing it. If your child is outgoing and difficult to manage, then that only means increasing your surveillance and knowledge of what they're up to.

Stop the teenagers trashing your house

Tips to ensure your party goes off without a hitch - and no Corey in sight!

• When sending out invitations, specify that you will have security present.
• Make entry to the party strict - partygoers must bring their invitation or photo identification to be allowed in.
• Notify police that you're having a party at least seven days prior to the day.
• Keep the guest list to a manageable size.
• Make sure the party has a definite start and finish time and stick to it.
• Check MySpace (www.myspace.com) and Facebook (www.facebook.com). If the party has been posted online, you'll need to take preventative measures, such as postponing the event or changing the venue.
• Make sure there's someone on hand who's trained in first aid.
• Ensure there's plenty of lighting. Ask your neighbours to turn on their outside lights so gatecrashers can't jump fences.
• Have one main entry and exit point and make sure it's kept clear at all times.
• It could be worth hiring private security personnel - costs vary from $40 up to $100 per hour per guard.
• Make sure the security company is licensed and that each guard is licensed.
• Also ensure the company you hire has public liability insurance.