The tragic deaths of two teenagers, who were amongst a group run down by a car at a party on Saturday night, have led to questions over how to control teenage parties.

Jane Young and Hannah Rossiter were killed when a car ploughed into a crowd of youths that gathered outside a Christchurch party. It is believed up to 500 people had gathered at the Edgeware Road party, with word being spread by text message and a sign on the fence outside the house in the week leading up to it.

Gatherings of that size are not uncommon around New Zealand, in fact just a few weeks ago another party in Christchurch attracted crowds of around 300.

Paul Dahl's nose, wrist and ribs were broken when he was attacked by a mob of teens outside the 300 strong party.

"There were a few people who were bored and pulling bus stop signs down and road signs and damaging people's property and I just stepped in to one or two guys that were dismantling a bus shelter and throwing it onto the road," he said.

"I fell to the ground and a number of them kicked a lot out of me...broke my wrist, damaged my face and did my ribs and my kidneys."

Dahl is not surprised at the weekend tragedy that subsequently unfolded in his city.

"The behaviour of one or two people were exactly the same...in the disrespect for other people."

It is not hard to work out how some parties are turning into big events.

Avondale College deputy principal Fiona Barker says schools have to start learning about texting and understanding the sort of etiquette and subtleties involved in "what is really a teenage form of communication".

Barker says students need to take some responsibility.

"Once you've sent a message you've actually got no control over who then has it...so from that respect it is prone to abuse."

Now New Zealand's mayors are mobilising to try and prevent a repeat of Saturday nights tragedy.

Nelson Mayor Paul Matheson, in his role as Chairman of the Mayor's Taskforce for Jobs, has called a meeting of civic leaders following the deaths of two 16-year-old girls when a car drove into a group of partygoers.

He says similar tragic events have affected many areas all over New Zealand and the issues concern everyone.

Matheson hopes the open forum will form some solutions to hopefully prevent anything like Saturday night from happening again.

Police bosses are also looking at alternatives to controlling teenage parties and have been for some time, though they say parents need to have firm control over what is happening.

"They need to have planned what's going to happen and discuss it with the children involved and keep a tight reign on things," says Superintendent Tony McLeod.

A youth worker agrees, saying parents of teenagers need to show a bit more tough love.

Youthtown executive director Keith Thorpe says with society becoming more liberal, many parents aren't setting and enforcing expected standards of behaviour for their teenagers. He says they back away from telling their children they are not allowed to go to parties because they don't want to alienate them.

Thorpe says for today's teens, what their peers think counts for much more than what their parents think.

An invitation to the civic leaders meeting has been extended to experts in the field of youth work and Matheson hopes the more people that are involved, the better the outcome will be.