Audio: How ambulances rushed to the scene after receiving desperate 911 call
It was 12.41am when the call came through.
"A balcony is broke and at least 10 people fell from the second or third floor," one emergency operator calmly called down the radio.
"A group of 10 or so possibly fell off a balcony at 2020 Kittredge Street," another repeated.
The San Francisco night was about to be lit up by ambulance lights and the sleepy suburb of Berkeley woken by the blare of sirens.
Emergency service operators were busy directing their first responders to the scene of a horrific accident, which wiped out the lives of six college students embarking on the adventure of a lifetime.
The hard-working men and women en route to the scene were clearly not expecting to find four lifeless bodies on the street when they arrived, with several others around them badly injured.
Police tapes reveal how, as they rushed to the scene, emergency services were trying to clarify which floor the accident occurred on and how this nightmare unfolded.
"Not sure if this is going to be a structural issue or if they were just playing out on the balcony and fell off," one operator could be heard saying, before his voice became distorted.
At this stage, just a few minutes into the 13-minute recording, the team of responders believed that 10 people had fallen off "a balcony that broke".
"They fell from the second or third floor," one operator added.
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More units were requested to deal with the witnesses who had gathered at the scene. They then began to attempt to take statements.
It is understood that one hour before the tragedy unfolded, the police had been called to the building to deal with a noise complaint.
"Three patients are here on the ground... they are on backboards, but need further treatment I think," one responder at the scene cut through.
Car alarms can be heard loudly in the background as teams of workers attempt to make communications from the scene.
"What do you think about having an investigator come in?" one man asked the chief officer. "Do you have a fire investigator or do you want a building investigator?
"I'll wait till you get here and we will talk face to face," the exchange continued.
We hear that other responders at the haunting scene made it in to the "unit", which had been "cleared".
"There is no one here," the officer added. "The unit is completely empty."
As the exchanges continued, we heard that a total of nine patients were transferred. We understand from the conversation that the officers discovered four deceased students.
The on-duty building inspector was contacted in the minutes after the accident and was expected to arrive at the scene within the hour. The scene was then just an empty apartment, as the friends of the victims travelled with their injured friends to nearby hospitals in the Bay area. Two more students later died in hospital.
On the street below the collapsed balcony lay pieces of rubble. One kind soul left a touching card which said the community was "so very sorry to hear of your loss of your friends".
"Here is a hug for each of you. Here are prayers for those in the hospitals. And here are prayers for those who have passed on."