Tabitha and Lucas Rainey were beginning to get suspicious.
The staff at Kentucky Children's Hospital kept telling them their infant son, Waylon, was recovering well from surgery. There had been a few bumps in the road, to be sure, but they said that was normal for a baby born with a severe heart defect.
Months passed. Waylon remained in the intensive care unit. More complications arose.
"Is everything OK?" the Raineys would ask.
Yes, the doctors and nurses assured them. Everything was fine.
Then one day, Tabitha Rainey says a cardiologist took her aside.
"She said, 'If I were you, I would move him,' " Rainey remembers. "She told me we should take him somewhere else.'"
A few days later, the Raineys arranged to have Waylon sent by helicopter to the University of Michigan. By then their son, not quite 3 months old, was in heart failure.
If Waylon Rainey had been born 30 years ago, he almost surely would have died a few days or weeks after birth. He has a condition called hypoplastic left heart syndrome, which means the left side of his heart is so malformed it can't pump blood.
Today, surgeons perform a series of three operations on babies like Waylon. They're high-stakes surgeries -- cutting into an organ the size of a newborn baby's fist is tricky, to say the least. The blood vessels can be thinner than a piece of angel hair pasta, and one wrong move, one nick, one collapsed artery or vein can be deadly.
These children are medically very fragile, and even the best surgeons lose patients. Surgeons track their deaths and complications and take great pride in the number of babies they save. Some are so proud they publish their success rates right on their hospital websites.
Kentucky Children's Hospital is not one of these hospitals.
Instead, Kentucky Children's Hospital has gone to great lengths to keep their pediatric heart surgery mortality rates a secret, citing patient privacy. Reporters and the Kentucky attorney general have asked for the mortality data, and the hospital has declined to give it to them. In April, the hospital went to court to keep the mortality rate private.
Parents of babies treated at Kentucky Children's say the hospital's effort to keep the data a secret, coupled with troubling events over an eight-week period last year, makes them suspicious something at the hospital has gone terribly wrong.
Four innocent lives
On August 30, Connor Wilson died after having surgery at Kentucky Children's Hospital for hypoplastic left heart syndrome. He was 6 months old.
Three weeks later, Waylon Rainey had his surgery and later went into heart failure.
Eleven days after that, newborn Jaxon Russell had a "botched" heart surgery at Kentucky Children's, according to his father.
Waylon and Jaxon both survived after undergoing additional surgeries elsewhere.
Less than three weeks later, on October 16, 6-month-old Rayshawn Lewis-Smith died after having heart surgeries at Kentucky Children's Hospital.
That same month, Dr. Mark Plunkett, the hospital's chief heart surgeon -- and the only surgeon performing open-heart surgeries at the hospital -- went on paid leave, according to hospital spokesman Jay Blanton, and the hospital stopped doing heart surgeries.
The parents say they didn't receive any explanation for why the surgeries stopped or why Plunkett left. A hospital spokeswoman said Plunkett was not available for comment.
CNN met with Connor, Waylon, and Jaxon's parents in Lexington, Kentucky.
"I think they're hiding something," says Nikki Crew, Connor's mother.