"She's devastated as well," said Poupouare.
Elliot played rugby for his school, was in the sports academy and had passed his diving certificate.
The party was at the Fife St home of Simon Beck, who last night said he wanted to speak to Elliot's family before making any comment.
The aftermath of the accident was chronicled online by a teenager named Rebecca, who was watching from her window. It was not until 12 hours after Elliot's death that she discovered she knew Elliot
Rebecca first posted on TradeMe at 11.42pm that media were outside her house. "No one else is up so I turn to you guys to keep me company. Very, very scary."
A few minutes later, she updated: "A couple just pulled up and ran into the house. Really hoping no one's seriously hurt (but cops keep turning up)." Then at 12.45am, she wrote: "Police all still outside. I'm heading to bed now, will see what's happening in the morning."
At 11.57am yesterday she wrote: "A 17-year-old boy died there last night but it wasn't a homicide. I don't think I should say too much more because it's so early. But he was one of my sister's best friends. So sad."
Western Springs College principal Ken Havill, who spoke with Elliot's parents yesterday, said the teenager displayed a natural intellectual curiosity and was interested in ideas.
"He was a personable, pleasant young man, popular with his peers and able to relate to a range of people," he said. "He was a competitive individual who was notably committed to the principles of fair play and the ethics of sportsmanship."
Havill said he had called a meeting today to plan for dealing with student grief.
"There will be a large number of distressed students. And it's exam week."
Distraught friends who gathered at a neighbour's house said there were around 20 teenagers at the Becks' home. They said Elliot had slipped in the bathroom and struck his head on the shower cubicle. They said the 17-year-old was not drunk when he fell but had been drinking.
St John Ambulance paramedics tried for almost an hour to resuscitate him.