A four-year-old boy went swimming. A week later he was dead.

A four-year-old Texan boy has died a week after he went swimming, in what his family claims is a case of “dry drowning“.

Francisco Delgado III was pronounced dead on Saturday at East Houston Regional Hospital after he suddenly stopped breathing.

Speaking to local TV news outlet, KTRK, the boy’s parents said he had experienced an upset stomach shortly after swimming at Texas City Dike the previous weekend, but seemed fine until he complained of a sore shoulder on Saturday morning.

“Out of nowhere, he just woke up. He said, ‘Ahhh’,” said Francisco’s father, Francisco Delgado Jr.

“He took his last breath and I didn’t know what to do no more.”

Paramedics and hospital doctors worked desperately to revive the boy as his mother, Tara Delgado, watched on.

"I walked in. I could see him lying there. They were still working on him. I'm screaming, 'Let me just touch my baby. Maybe he needs his mama's touch," she told KTRK.

"When she came in, she told us it's what's called dry drowning. His lungs were full of fluid. There was nothing else they could do for him."

Medical examiners are yet to release the results of a post mortem.

Despite popular understanding, drowning is not always immediately fatal. In fact, it's not necessarily fatal at all. Health care practitioners generally accept the definition that drowning is simply "the process of experiencing respiratory impairment from submersion/immersion in liquid."

As Dr. Kay Leaming-Van Zandt of Texas Children's Hospital explained to KTRK, "Some children will have symptoms soon after the drowning occurs. Some children will have symptoms later on. They may seem fine. They develop respiratory issues hours after the event."

This was once commonly referred to as "dry" or "secondary" drowning, but healthcare practitioners have been abandoned those terms recent years in order to streamline the reporting process and ensure drowning fatalities are recorded as such.

Now known as non-fatal drowning, symptoms include difficulty breathing, excessive cough, foam or froth in the mouth and stomach upset within hours of being in the water.