They used boards to shore up the sides of the seven-foot trench he had dug and which collapsed over his head after he jumped in. Maly, who competed in the 2010 Youth Olympics in Singapore and is now on the Austrian Olympic swimming squad, was given an oxygen mask to help him breathe during the dramatic rescue on Sunday evening at Pompano Beach, Florida.

He spent a night in hospital before flying back to his home in Austria where he was recovering. "He is an Olympic swimmer so I suppose he digs Olympic size holes," Pompano Beach Fire and Rescue spokeswoman Sandra King told Reuters on Tuesday.