By Kris Jepson
Three-week-old baby, Carter Cookson, has died in hospital following an appeal to find a new heart for transplantation.
Carter was born on Boxing Day, but suffered three cardiac arrests in the hours after his birth.
On Saturday evening his parents, Sarah and Chris Cookson, from South Shields, posted on Facebook to say he had lost his "fight" for life.
The post entitled "RIP Carter John Cookson" said:
“Today he could not fight anymore... at 5.44pm our brave baby boy Carter John Cookson gained his angel wings and flew into his big brother's arms.
"We are heart broken... our two boys are in heaven without their Mammy and Daddy we feel so empty and our hearts will never recover.
"No more pain baby boy, No more tubes... be free with your big brother and Granda... until we can all be together again. You have taken our hearts with you... we will never recover."
Carter had a pacemaker fitted, but failed to respond to surgery. As a result he to be assisted by a special machine called an "Ecmo", which enabled his heart to pump blood around his body.
However, the Ecmo machine carried with it a high chance of infection or blood clots forming within the circuit, so on a day-to-day basis consultants had to make sure no clots were found in the circuit and the circuit was free of infection.
Carter's parents said on Thursday that due to complications with Carter's connection to the machine, surgeons were unable to change the Ecmo again if anymore clots formed in the circuit, meaning they had a race against time to find a new heart.
Carter's unexpected and devastating heart problems came as the cruelest of blows for the Cooksons, who lost their first son Charlie in 2013 when he was just two-and-a-half.
After Charlie’s death, the couple set up the Charlie Cookson Foundation in a bid to support other families with seriously ill children.
On Friday night, the couple had said they were trying to focus on spending time with Carter, who they feared only had days to live, at the Freeman Hospital, in Newcastle.
Their Facebook post read: “Our hearts are breaking… as once again no phone call… and another day closer to losing our baby.”
Earlier this month Sarah Cookson told ITV News "the cruelest thing is he (Charlie) had everything wrong with the rest of his body, but the one thing that was strong, was his heart, and his brother (Carter) has come back with the one thing that’s the weakest is his heart and everything else is perfect."
Thousands of people posted their condolences on the social media site beneath a final photograph of Carter.
The couple thanked everyone who had tried to help on their Find a Heart for Carter page, saying: “Thank you to everyone who has helped to try and find Carter’s gift we will be eternally grateful xxx”