Experts have criticised the standard of trauma care in the NHS, after a study found too many patients were not given the right tests or seen by suitably experienced staff after being admitted.
The McGinns had gone to bed when the phone rang shortly before 1am.
It was a local hospital informing them their 16-year-old son Graeme had fallen off his motorbike.
They were reassured that it was not too serious and he had just broken his arm.
Graeme's father, Tony, 49, from Eastleaze in Swindon, said: "When we got to hospital he seemed OK. He was conscious and he knew who we were.
"He was apologetic and just said he was thirsty and wanted a drink.
"But his condition changed very quickly.
"He seemed to be getting aggressive. His language was more colourful. And he started complaining of a pain in his chest. He said someone was sitting on his chest."
Staff decided to give him a chest X-ray, but Graeme started thrashing around and someone had to hold him down.
And just after, as Tony and his wife were stepping outside for some fresh air, the alarm went off.
The McGinns were told staff were giving their son a heart massage as his heart had stopped.
But before long they were being told the news they dreaded.
"I had started praying, but just before 5am three doctors told us he had died.
"We had to go through all the formalities and all the time I was thinking this is wrong."
It transpired that Graeme had died from internal injuries that had not been diagnosed.
Mr McGinn said he believes the hospital did not take the case seriously enough.
"They thought he was another 16-year-old who had had too much to drink. They did not seem overly concerned."
Later he was told his son may well have survived if his injuries from the accident in May 2004 had been identified earlier.
"A pathologist said he was fit and well nourished and should not have died from his injuries.
"I believe if they had picked up on the injuries soon enough he would have survived."
And Mr McGinn said the findings of the National Confidential Enquiry into Patient Outcome and Death do not surprise him.
The report has revealed over half of patients are not given good enough treatment as staff are often too inexperienced.
He said: "It is all about money these days. But everybody pays their taxes. There should be enough money to do the jobs properly."