The five-month-old brothers, named locally as Noah and Charlie, were rushed to hospital from their home in Bridgend on Saturday. They were pronounced dead by medical staff later in the day, police said.
The two five-month-old triplets found dead at their home were not killed by carbon monoxide poisoning.
Police have revealed that five-month-old boys Noah and Charlie died in their sleep after a 'tragic accident' - but that their deaths were not a result of the toxic gas.
Their heartbroken mother, Sarah Owen, 29, found the boys not breathing when she checked on them.
A neighbor said: “It is a terrible tragedy. The young girl was a single parent and had only been in there a short time. She often wheeled the triplets around the estate. She doted on them. I saw emergency crews take the bodies out and it was a terrible sight.”
Emergency crews rushed them to a hospital with their brother Ethan, who survived.
Another neighbor, Ann May, 64, said: “I saw the mother and she is absolutely distraught. The fire service was here, but there was no fire. I saw those poor babies being brought out. It was so shocking. I tried to speak to their mother but she was too upset.”
Officers arrived at the property after receiving a 999 call shortly after 10 am.
Firefighters and medics were also in attendance at the scene. The two tots were reportedly rushed to the Princess of Wales hospital in Bridgend but they were tragically pronounced dead.
“There are no suspicious circumstances surrounding the deaths, which are being treated as a tragic accident.”
Detective Inspector Dean Taylor said: “Enquiries are continuing into what caused the young boys’ tragic deaths. At this moment in time, there is nothing to suggest that carbon monoxide poisoning was the cause. In fact, there is nothing that leads us to believe that this was anything other than a tragic accident."
The children's godmother Siobhan Boyd has set up a GoFundMe page to support mum Sarah through the tragedy.
Writing on a fundraising site, which aims to source £5,000 to help pay for funeral costs, Boyd said: "Sadly this morning (Saturday) two of my beautiful godsons passed away. I'm trying to raise money for their mother to help with the costs of flowers etc. If anybody would like to help hopefully we can raise enough to take the financial stress off Sarah at this difficult time. Thank you all for reading xxx"
The family, who had only been there since April, were to be re-housed because the home had recently been sold.
A Home Office pathologist has been called in to carry out a post-mortem examination on the two babies. A file is due to be prepared for Glamorgan coroner Andrew Barkley and an inquest is expected to be opened next week.
