Thomas Jr said his father was lying on the floor in “agonising, groaning pain in front of everybody”.
“I asked for a screen to be put up in the hospital for his dignity because he was a very proud man,” he said.
“But the doctor looked at me and said, ‘Tell [the other patients] to look the other way then’.”
Thomas Jr added: “They didn’t care about him. They left him like a dog rolling around on the floor. It was inhumane.”
He said he realised that his father had suddenly gone quiet.
“[I will never forget] the gruesome sight of my father on the floor, blue in the face with white froth dripping from his mouth,” Thomas Jr told the BBC.
The 19-year-old said CPR was then administered by medical staff on the waiting room floor, before his father was moved through double-doors next to the waiting room, where he was declared dead soon afterwards.