We have learned more about that now notorious back to school pool party, from three people who were there.
"The pool just became a mass of people," said student Robert Lopez.
"I've never seen anything like this," said Brandon Frank.
When these three buddies arrived at the pool at an apartment complex in Fort Collins, Colorado, the party was already jumping.
"When we got there there was probably about 800, 900 people already there. As the day progressed more people kept flooding in," said Lopez.
At its height, an estimated 4,000 people, most of them students from Colorado State University, were packed in, the numbers swollen by social media messages.
Brandon Vue said "There was a lot of people mainly because of Facebook. The event page was open to the public. It had the location, it had the time."
"It definitely became bigger because of Facebook, but I never in a million years thought this many people would go," explained Frank.
"When we got there the pool was like regular water, you can see into the water, and you could see the bottom of the pool; by the time, I left the water had turned grey. Beer cans and stuff floating in it," said Lopez.
Organizers had hired security and the party was supposed to be alcohol-free.
"It clearly said on the Facebook page, no alcohol allowed," said Frank.
But the warning had little effect on some of the students. Ten were treated for heavy drinking.
"There was a good amount of people drinking," said Vue.
"You're sitting there, can barely move, alcohol everywhere," Lopez said.
These are the just-released 911 calls:
911 Caller: "We have someone passed out. He needs medical attention."
Caller: "He's at the pool house."
Caller: "He's over-intoxicated and he passed out, throwing up."
It wasn't just the guys who were overindulging.
Caller: "We've got somebody in the bathroom puking."
911 Operator: "In the females bathroom?"
Four people were arrested.
Today, the apartment complex is quiet. Only a couple of guys were at the pool. And you can bet things will be different for next year's party.
"Maybe it's strictly to residents, and not publicly displayed on Facebook," said Frank.
The management of the apartment complex where the party was held told us in a statement that they took precautions to manage security and regret that safety was put at risk by some who violated the rules.