It was a cruel “dry drowning” accident when a 10-year-old South Carolina boy died of "drowning" more than an hour after he left the swimming and was walking home with his mother.

Johnny Jackson, a teenage boy from South Carolina died of "dry drowning," which is a form of asphyxiation that happens when a small amount of water gets into the lungs and damages tissue, causing the lungs to swell and fill up with water.

The boy's mother, Cassandra Jackson told Thursday that Johnny went to swimming in a local pool at Goose Greek on Sunday. He walked home with her and his sister, and after she bathed him he told her he felt sleepy. When she went to check on him later she saw his face was covered in a "spongy white material." He was rushed to hospital but died of cardiac arrest on the way. Cassandra Jackson said, "I've never known a child could walk around, talk, speak and their lungs be filled with water."

According to the doctors, Johnny must have got some water in his lungs while he was swimming in his local pool at Goose Greek, South Carolina. He didn't show any signs of respiratory distress, but he had an accident in the pool and "soiled himself".

The doctors believe when water gets into lungs accidentally, like it had in Johnny's case, the lungs can't bring oxygen to the blood or the brain. The water can flood the lungs up to 24 hours after swimming or bathing. In very rare cases, it can also occur following a bath. Sometimes water enters the windpipe after diving or jumping into a pool, and sometimes forced pressure on the front of the neck during swimming can cause the accident.

Thus, the experts recommend not letting a child swallow too much pool or bath water. Parents should look out for symptoms including difficulty breathing, extreme tiredness, and changes in behavior, which result from the brain not getting enough oxygen because of water in the lungs.