Seven times, teenage hiker David Iredale used his cell phone to call Australia's equivalent of 911, pleading for rescue after he became lost in tough scrubland and ran out of water in 100-degree heat.

Each time he got through, he was told he needed to give a street address before an ambulance could be sent. Shortly after the final call, Ireland collapsed and died of thirst.

An inquiry into the 2006 death of the 17-year-old exposed deep flaws in the country's emergency response system, including what a coroner called an astonishing lack of empathy by the operators who took his increasingly desperate calls for help.

Officials in New South Wales state on Friday acknowledged the system's failure and promised to overhaul it. Iredale's father said preventing similar tragedies in the future would be a legacy his son deserved.

A wilderness enthusiast and member of Sydney Grammar School's rowing team, Iredale set off with two classmates on a summer vacation camping trek in the Blue Mountains, a picturesque but notoriously harsh landscape of eucalyptus-shrouded peaks and gorges 80 miles west of Sydney.

It was supposed to take three days and earn the boys points toward the Duke of Edinburgh Award, an international program to promote leadership and good character.

They were well-prepared with camping gear, maps and plenty of food. The two less experienced hikers carried water in plastic bottles, while Iredale had a 4-pint (two-liter) hiker's water bag strapped to his back.

According to testimony to the coroner's inquiry from the two survivors, the hikers' water ran dry on the first day as temperatures rose to 100 F (37 C) and they slurped it down while marching across rocky terrain and tree-lined trails. After camping for the night, they pressed on toward a river they expected to reach within a few hours on the second day.

Iredale, fitter and more experienced, kept darting ahead of his colleagues and waiting for them to catch him up, they told the inquiry. When they eventually reached the river Iredale was not there.

How Iredale became lost is not clear. But when he did, he turned to what many would consider a modern-day lifeline: his cell phone.

In audio records of his calls to "000" — Australia's version of the 911 emergency line — Iredale tells ambulance officials he has lost the trail and is surrounded by "the bush."

Dialing from deep in a gorge, Iredale's connection kept dropping out, ambulance officers told coroner Carl Milovanovich, who began his inquiry last month.

Iredale's first call to triple-0 was put through to police and quickly cut out, though not before he was able to convey that he was stuck near a peak called Mount Solitary — information that eventually helped triggered a search.

Over the next hour or so, he called triple-0 six more times. Once the call was diverted to a recorded message. Five times he was connected to the New South Wales state Ambulance Service.

Milovanovich's 35-page report released Thursday recounts the calls, and Iredale's rising anguish as time and again operators "interrogated" him about a street name that could be entered into the service's computer. He could only name the walking trail and Katoomba, the town where the trio began their trek.

On the third call, an obviously distressed Iredale tells operator Laura Meade: "I'm lost. I need water. I haven't had water for a long period of time."

She interrupts him to ask, "Sir, do you need an ambulance?" When he says yes, Meade asks for a suburb and street name, which prompts Iredale to yell that he is not in a town. Then the connection drops out.

Iredale called back and cried out, "Hey, this is an emergency ... emergency!" before the line dropped out again.

During the final call, Iredale, groaning audibly and breathing heavily, tells the operator he had fainted and needed a helicopter, Milovanovich's report says. She put him on hold twice before then line dropped out.

After this call, ambulance officials contacted the police and the two services began cooperating on a search. Police planes flew over the area, and a major ground search began.

Eight days later, Iredale's body was found slumped against a tree.

Milovanovich said he did not want to criticize the individual ambulance operators, instead blaming a system he said did not allow them to override a computer that demanded a street name before an ambulance could be dispatched.

"The relentless focus of all the call-takers in further attempting to establish an address or precise location, having regard to the nature of the calls, was astonishing," Milovanovich said.

The operators "lacked empathy" because they were too preoccupied with the computer, he said. Operators should be trained to override the computer and to recognize signs of illness or distress in callers.

Ambulance service chief executive Greg Rochford said all of Milovanovich's recommendations would be implemented "as swiftly as we can."

"The ambulance service sincerely and unreservedly apologizes for the deficiencies in the way the service managed this case and for the hurt that was clearly caused to the Iredale family," Rochford told reporters.

David's father, Stephen Iredale, declined to criticize the ambulance service but said he hoped the inquiry would help prevent anyone suffering a similar fate to his son.

"We hope that this will result in a useful legacy for David," he told reporters after the coroner's report was released.