One of Britain's best-known broadcasters Nicky Campbell has revealed that he and his radio colleagues were moved to tears yesterday by a Lurgan mother's emotionally-charged interview about the death of her son from asthma.
And afterwards Donna Green told the Belfast Telegraph: "The response to the interview about Tiernan has been astonishing. I only hope that my message about asthma gets through.
"If I can save one life that would be a big thing for me. I think I get my strength to talk publicly from my son."
Veteran presenter Campbell told listeners to his Radio 5 Live programme that Donna's powerful plea for asthma sufferers to take their proper medication was "amazing, moving and incredible", and would undoubtedly save lives.
"There wasn't a dry eye here listening to that," he said.
Donna broke down as she talked of her horror at battling in vain to save the 20-year-old after he suffered an attack in January last year.
She was speaking after Asthma UK issued a report saying that nearly two-thirds of people with the condition are still not receiving the basic level of care they need despite claims it could prevent two out of three asthma deaths a year. Asthma UK's study said there was a "frustrating" lack of progress.
Tiernan was one of 1,200 asthma deaths in the UK last year.
According to the survey, Northern Ireland had the best performance for best care across the UK, with 48.2% of patients receiving basic care.
After Tiernan passed away his mother posted a poignant video on Facebook that went viral and received more than a million views and shares.
Yesterday there was a huge response from radio listeners after Donna talked to Rachel Burden, Campbell's co-host on the 5 Live breakfast show, about how the talented Gaelic footballer passed away despite her and her husband Stephen going to his aid at their Derrymacash home in Co Armagh. She said: "He came in that morning about two o'clock and the two of us actually spoke, but he came to my bedroom about 3.30 gasping for breath.
"At first I thought he was hyperventilating but I realised he was having an asthma attack.
"I knew he needed medical attention so I dialled 999 but I could see his condition was getting worse.
"His lips and ears were blue. He was very pale and the veins were standing out on his forehead."
Tiernan looked at himself in the mirror and Donna recalled him saying: "Mummy, I'm going to die tonight."
Donna administered CPR for 10 minutes until the ambulance crew arrived, but Tiernan's heart had stopped.
He was rushed to hospital where doctors told his distraught family that, in spite of their best efforts, he was gone.
Fighting back tears, Donna said: "One minute your son is standing in front of you, fighting for life, and the next he is gone. It's heartbreaking.
"But I am trying to do my best to get it out there for people - even adults - please, please start taking your medication the doctor prescribed you, even if you feel as well as Tiernan did most days."
In the interview, which was repeated later yesterday morning, Donna also urged asthma sufferers to keep in regular contact with their doctors to ensure they had the correct care plan. Donna said Tiernan was born with asthma but his condition was initially under control and he attended a nurse regularly.
She said, however, that he didn't take his brown preventer inhaler, which contained steroid medication, because he felt it made no difference.
"He said the blue one (reliever inhaler) helped him more," added Donna, who said that a post mortem found that Tiernan had used his blue inhaler 30 times on the day of his fatal attack, and she thought his body had become immune to it.
Donna added: "I think if he was using his brown inhaler over the years Tiernan would still be with us today."
Tragically, the inquest into Tiernan's death heard that he had an asthma review lined up with his specialist nurse but died before he had the chance to go.
Donna said that two of her three other children Stefan (25) and Ryan (9) had lesser problems with asthma and their conditions were well under control.
She and Stephen launched an awareness campaign about asthma last year and gathered enough money to get 80 lifesaving nebulisers installed in schools.
They also organised a 135-vehicle truck run, which raised £22,000 for a respiratory machine for Craigavon Hospital.
This year they will be fundraising for a bereavement counselling charity in Armagh.
Next week Donna and her family will quietly mark the first anniversary of Tiernan's death.