US boy's 'dry drowning' death prompts warning for parents

There's a warning for parents after a US family lost their four-year-old boy to 'dry drowning' days after swallowing seawater during a beach trip.

Preschooler Frankie Delgado was briefly knocked over while in knee-deep water in Texas in late May when a wave knocked him over.

His family thought everything was fine until the next day when the boy started complaining about stomach pain, began to vomit and had diarrhoea.

It wasn't until about a week later things took a turn for the worse.

"Out of nowhere he just woke up and he said 'ahhhh' and he took his last breath. I didn't know what to do no more," his dad Francisco Delgado said.

Frankie was taken to hospital, but died a short time later of what's suspected to be 'dry' or 'secondary' drowning where water is inhaled into the lungs then become irritated and fill with fluid.

Symptoms include coughing, chest pain, troubled breathing and feeling tired.

Doctors say the condition is extremely rare, but is more common in children than adults because of their size.

Mr Delgado told CNN he hoped to raise awareness about dry drowning and his son's story to stop others from going through the same thing.

"My son was special. My son was so good. He was the best," he said. "All he wanted to do was put a smile on my face."

And Frankie's story has already been credited for saving a Colorado two-year-old after his father, Garon Vega noticed the same symptoms in his son.

Mr Vega has seen stories about Frankie and told ABC News his son had been swimming as well and had swallowed water.

He started getting a fever and had trouble breathing, so Mr Vega took him to hospital where he received the necessary treatment.

"I feel like I needed to reach out to the parents of little Frankie and tell them, I don't know how to word it, but their little boy saved our little boy's life," Mr Vega told ABC.